Smart intercom stations for legacy intercom systems

ABSTRACT

Smart buzzer systems for apartment buildings, where an intercom station in an apartment unit notifies the user of a request from a guest to unlock the building&#39;s door, sends the user&#39;s approval of the request to the door, and enables the user and the guest to talk to each other, are disclosed. The smart buzzer systems are enhanced with connectivity with mobile devices and mobile applications as well as automation. The intercom station includes an audio input-output circuit configured to process audio signals, which includes a line input buffer configured to process audio signals from a legacy base microphone through a wiring interface for a legacy intercom system to a processor and a line output driver configured to process audio signals from the processor to the legacy base speaker through the wiring interface fertile legacy intercom system.

FIELD OF THE INVENTION

Embodiments of the present invention are in the field of intercomstations that use artificial intelligence, signal processing, electronicsystems, and/or mechanical systems to manage door and gate entry systemsinto buildings and complexes.

BACKGROUND OF THE INVENTION

The statements in the background of the invention are provided to assistwith understanding the invention and its applications and uses, and maynot constitute prior art.

“Buzzer” systems for buildings (e.g., apartments, commercial offices,and recreational facilities) and complexes (e.g., gated communities,groups of office buildings) —where an intercom station in a unitnotifies the user of a request from a guest to unlock the building'sdoor or gate, sends the user's approval of the request to the door orgate, and enables the user and the guest to talk to each other—are astandard technology used in many older apartment buildings. In theInternet age, many users desire a buzzer system that takes advantage ofmodern technology, such as integration with mobile devices andapplications (“apps”) and automation, which provides the possibility ofadditional features. However, in many cases, upgrading the entireintercom system of an apartment building requires high hurdles to bemet, such as difficulty and cost in physically installing a new intercomsystem, or negatively impacting the aesthetic or historic look of thefront of the building.

Therefore, it would be an advancement in the state of the art to providea technology where an individual user in an apartment unit of a buildingwith a traditional intercom system, such as one that merely permits auser to speak to a guest and buzz the guest in, is able to upgrade to a“smart” buzzer system by replacing, modifying, or supplementing only thepre-existing resident unit-level intercom station with an enhancedintercom station that is compatible with the rest of the intercomsystem's components, wiring, and operation. Users need to retrofit onlywhat they have access to in the units (the unit intercom station), whichlimits disruption to the building by avoiding having to rewire orreplace the building-wide system. The technology may be readily deployedin non-residential buildings and complexes as well.

It is against this background that the present invention was developed.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to an intercom station apparatus. Morespecifically, in various embodiments, the intercom station apparatusconnects to a legacy intercom system, and includes a station audioemission subsystem configured to emit a first audio signal; a stationaudio reception subsystem configured to receive a second audio signal; atalk feature configured to activate the station audio receptionsubsystem and a legacy base speaker; a listen feature configured toactivate a legacy base microphone and the station audio emissionsubsystem; a wiring interface for the legacy intercom system; aprocessor configured to interact with and control the station audioemission subsystem and the station audio reception subsystem; and anaudio input-output circuit configured to process audio signals,including: a line input buffer configured to process audio signals fromthe legacy base microphone through the wiring interface for the legacyintercom system to the processor, including: a first electrostaticdischarge and transient protection subcircuit configured to receive afirst input signal from the wiring interface for a legacy intercomsystem; a first galvanic isolator and voltage scaler subcircuit; and afirst voltage buffer coupled to the first galvanic isolator and voltagescaler subcircuit, wherein the first voltage buffer is configured totransmit a first output signal to the processor; and a line outputdriver configured to process audio signals from the processor to thelegacy base speaker through the wiring interface for the legacy intercomsystem, including: a second voltage buffer configured to receive asecond input signal from the processor; a high-pass filter coupled tothe second voltage buffer; a second galvanic isolator and voltage scalersubcircuit coupled to the high-pass filter; and a second electrostaticdischarge and transient protection subcircuit coupled to the secondgalvanic isolator and voltage scaler subcircuit and configured totransmit a second output signal to the wiring interface for the legacyintercom system.

In some embodiments, the station audio emission subsystem is a stationspeaker, the first audio signal is sound, the station audio receptionsubsystem is a station microphone, and the second audio signal is sound.

In some embodiments, the first voltage buffer is a first operationalamplifier, and the second voltage buffer is a second operationalamplifier.

In some embodiments, the first electrostatic discharge and transientprotection subcircuit includes a first electrostatic discharge resistorand a first transient-voltage-suppression diode, and the secondelectrostatic discharge and transient protection subcircuit includes asecond electrostatic discharge resistor and a secondtransient-voltage-suppression diode.

In some embodiments, the first galvanic isolator and voltage scalersubcircuit includes a first transformer, and the second galvanicisolator and voltage scaler subcircuit includes a second transformer.

In some embodiments, the first transformer is 1:1.

In some embodiments, the second transformer is 1:1.

In some embodiments, the first galvanic isolator and voltage scalersubcircuit further includes a first voltage scaler coupled to the firsttransformer, and the second galvanic isolator and voltage scalersubcircuit further includes a second voltage scaler coupled to thesecond transformer.

In some embodiments, the first voltage scaler includes: a first voltagedivider coupled to the first transformer, and a second voltage dividercoupled to the first voltage divider; and the second voltage scalerincludes a third voltage divider.

In some embodiments, the first voltage divider includes a plurality ofresistors, and the first voltage divider generates a ratio ofapproximately 50%.

In some embodiments, the second voltage divider includes a plurality ofresistors.

In some embodiments, the second voltage divider biases a signal toaround half of a supply voltage.

In some embodiments, the third voltage divider includes a plurality ofresistors, and the third voltage divider generates a ratio ofapproximately 4.5%.

In some embodiments, the high-pass filter includes a capacitor with acapacitance based on an impedance of the second transformer.

In some embodiments, the second transformer includes a plurality ofwindings, and a DC resistance of each winding of the plurality ofwindings of the second transformer is greater than a resistance of alegacy station speaker.

In some embodiments, the second transformer supports a signal range of200 Hz to 4,000 Hz.

In some embodiments, the line input buffer further includes avoltage-limiting subcircuit coupled to the first voltage buffer, and thevoltage-limiting subcircuit limits an input to the first voltage bufferto within a predefined threshold.

In some embodiments, the voltage-limiting subcircuit includes a Schottkybarrier diode.

In some embodiments, the intercom station apparatus is configured tointeract with a base and a backend cloud-computing service (CCS).

In various embodiments, the intercom station apparatus connects to alegacy intercom system, and includes a station audio emission subsystemconfigured to emit a first audio signal; a station audio receptionsubsystem configured to receive a second audio signal; a talk featureconfigured to activate the station audio reception subsystem and alegacy base speaker; a listen feature configured to activate a legacybase microphone and the audio emission subsystem; a wiring interface forthe legacy intercom system; a processor configured to interact with andcontrol the station audio emission subsystem and the station audioreception subsystem; and an audio input-output circuit configured toprocess audio signals, including: a line input buffer configured toprocess audio signals from the legacy base microphone through the wiringinterface for the legacy intercom system to the processor, including: afirst galvanic isolator and voltage scaler subcircuit configured toreceive a first input signal from the wiring interface for a legacyintercom system; and a first voltage buffer coupled to the firstgalvanic isolator and voltage scaler subcircuit, wherein the firstvoltage buffer is configured to transmit a first output signal to theprocessor; and a line output driver configured to process audio signalsfrom the processor to the legacy base speaker through the wiringinterface for the legacy intercom system, including: a second voltagebuffer configured to receive a second input signal from the processor; ahigh-pass filter coupled to the second voltage buffer; and a secondgalvanic isolator and voltage scaler subcircuit coupled to the high-passfilter and configured to transmit a second output signal to the wiringinterface for the legacy intercom system.

Other aspects and embodiments of the present invention include themethods and processes comprising the steps described herein, and alsoinclude the processes and modes of operation of the systems and devicesdescribed herein.

Yet other aspects and embodiments of the present invention will becomeapparent from the detailed description of the invention when read inconjunction with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention described herein are exemplary, andnot restrictive. Embodiments will now be described, by way of examples,with reference to the accompanying drawings, in which:

FIG. 1A shows an overall view of an exemplary intercom station within anexemplary legacy intercom system, in accordance with some embodiments ofthe invention.

FIG. 1B shows a schematic of an exemplary intercom station interactingwith a backend, a mobile application, and other services, in accordancewith some embodiments of the invention.

FIG. 2A shows an isometric view of an exemplary intercom station with atrim plate, in accordance with one embodiment of the invention.

FIG. 2B shows a front view of an exemplary intercom station with a trimplate, in accordance with one embodiment of the invention.

FIG. 3A shows views of an exemplary apartment unit before and after theinstallation an exemplary intercom station, in accordance with someembodiments of the invention.

FIG. 3B shows an exemplary pre-existing intercom station installed inthe wall of an apartment unit, in accordance with some embodiments ofthe invention.

FIG. 3C shows an exemplary pre-existing intercom station being unscrewedfrom the wall of an apartment unit, in accordance with some embodimentsof the invention.

FIG. 3D shows an exemplary pre-existing intercom station with wireslabelled, in accordance with some embodiments of the invention.

FIG. 3E shows an exemplary pre-existing intercom station with wiresdisconnected, in accordance with some embodiments of the invention.

FIG. 3F shows a trim plate of an exemplary intercom station beingaligned with the wall of an apartment unit, in accordance with someembodiments of the invention.

FIG. 3G shows a trim plate of an exemplary intercom station installedinto the wall of an apartment unit, in accordance with some embodimentsof the invention.

FIG. 3H shows a mounting plate of an exemplary intercom station beingaligned with a trim plate mounted onto the wall of an apartment unit, inaccordance with some embodiments of the invention.

FIG. 3J shows a mounting plate of an exemplary intercom stationinstalled into a trim plate mounted onto the wall of an apartment unit,in accordance with some embodiments of the invention.

FIG. 3K shows an enclosure of an exemplary intercom station beingaligned with a mounting plate, in accordance with some embodiments ofthe invention.

FIG. 3L shows an enclosure of an exemplary intercom station installedonto a mounting plate, in accordance with some embodiments of theinvention.

FIG. 4A shows a first-level functional block diagram of the varioussubsystem components of the exemplary intercom station, in accordancewith some embodiments of the invention.

FIG. 4B shows a second-level functional block diagram of the varioussubsystem components of the exemplary intercom station, in accordancewith some embodiments of the invention.

FIG. 4C shows a functional block diagram of the exemplary intercomstation with separate universal relay and audio isolation subsystems, inaccordance with some embodiments of the invention.

FIG. 4D shows a functional block diagram of the exemplary intercomstation with combined universal relay and audio isolation subsystems, inaccordance with some embodiments of the invention.

FIG. 5A shows an exemplary functional block diagram of the variouselectrical components of the exemplary intercom station, in accordancewith some embodiments of the invention.

FIG. 5B shows an exemplary circuit diagram of the line input buffer andline output driver of the exemplary intercom station, in accordance withsome embodiments of the invention.

FIG. 5C shows an exemplary circuit diagram of the tone detectionsubsystem of the exemplary intercom station, in accordance with someembodiments of the invention.

FIG. 5D shows an exemplary circuit diagram of the universal relaysubsystem of the exemplary intercom station, in accordance with someembodiments of the invention.

FIG. 5E shows an exemplary circuit diagram of the audio isolationsubsystem of the exemplary intercom station, in accordance with someembodiments of the invention.

FIG. 5F shows an exemplary circuit diagram of the combined audioisolation and universal relay subsystems of the exemplary intercomstation, in accordance with some embodiments of the invention.

FIG. 6A shows exemplary electrical waveforms of a door buzz signal fromthe intercom station of an exemplary legacy intercom system, inaccordance with some embodiments of the invention.

FIG. 6B shows an exemplary electrical waveform of a door ring signalfrom the lobby panel of an exemplary legacy intercom system, inaccordance with some embodiments of the invention.

FIG. 6C shows exemplary electrical waveforms of a door ring signal fromthe lobby panel of an exemplary legacy intercom system and the responsefrom the tone detection subsystem of an exemplary intercom station, inaccordance with some embodiments of the invention.

FIG. 6D shows an exemplary electrical waveform of a user yelling intothe microphone of the lobby panel of an exemplary legacy intercomsystem, in accordance with some embodiments of the invention.

FIG. 7A shows a schematic of various components of an exemplary intercomsystem, including components of an exemplary intercom station, when aguest speaks to a user, in accordance with some embodiments of theinvention.

FIG. 7B shows a schematic of various components of an exemplary intercomsystem, including components of an exemplary intercom station, when auser speaks to a guest, in accordance with some embodiments of theinvention.

FIGS. 8A, 8B, 8C, 8D, 8E, 8F, 8G, and 8H show exemplary message journeysfor various use cases of the exemplary intercom station, in accordancewith some embodiments of the invention.

FIG. 9A shows an exemplary home screen of a graphical user interface(GUI) of an intercom station mobile app, in accordance with someembodiments of the invention.

FIG. 9B shows an exemplary “buzzing” screen of a GUI of an intercomstation mobile app, in accordance with some embodiments of theinvention.

FIG. 9C shows an exemplary “buzzed” screen of a GUI of an intercomstation mobile app, in accordance with some embodiments of theinvention.

FIG. 9D shows an exemplary “talking” screen of a GUI of an intercomstation mobile app, in accordance with some embodiments of theinvention.

FIG. 9E shows an exemplary “listening” screen of a GUI of an intercomstation mobile app, in accordance with some embodiments of theinvention.

FIG. 10A shows an exemplary “keys” screen of a GUI of an intercomstation mobile app, in accordance with some embodiments of theinvention.

FIG. 10B shows an exemplary “issue new key” screen of a GUI of anintercom station mobile app, in accordance with some embodiments of theinvention.

FIG. 10C shows an exemplary “share key” screen of a GUI of an intercomstation mobile app, in accordance with some embodiments of theinvention.

FIG. 10D shows an exemplary “deactivate” screen of a GUI of an intercomstation mobile app, in accordance with some embodiments of theinvention.

FIG. 10E shows an exemplary “activity history” screen of a GUI of anintercom station mobile app, in accordance with some embodiments of theinvention.

FIG. 11 shows an illustrative flow diagram for unlocking a door using anintercom system from a station, in accordance with one embodiment of theinvention.

FIG. 12 shows an illustrative flow diagram for remotely unlocking a doorusing an intercom system, in accordance with one embodiment of theinvention.

FIG. 13 shows an illustrative flow diagram for automatically unlocking adoor using an intercom system, in accordance with one embodiment of theinvention.

FIG. 14 shows an illustrative flow diagram for unlocking a door using anintercom system with a virtual key, in accordance with one embodiment ofthe invention.

FIG. 15 shows an illustrative flow diagram for unlocking a door using anintercom system with a spoken password, in accordance with oneembodiment of the invention.

FIG. 16 provides a block diagram of a server (management computingentity) according to one embodiment of the present invention.

FIG. 17 provides an illustrative schematic representative of a client(user computing entity) that can be used in conjunction with embodimentsof the present invention.

FIG. 18 shows an illustrative system architecture diagram forimplementing one embodiment of the present invention in a client-serverenvironment.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the figures provided, embodiments of the presentinvention are now described in detail.

In the following description, for purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of the invention. It will be apparent, however, to oneskilled in the art that the invention can be practiced without thesespecific details. In other instances, structures, devices, activities,and methods are shown using schematics, use cases, and/or flow diagramsin order to avoid obscuring the invention. Although the followingdescription contains many specifics for the purposes of illustration,anyone skilled in the art will appreciate that many variations and/oralterations to suggested details are within the scope of the presentinvention. Similarly, although many of the features of the presentinvention are described in terms of each other, or in conjunction witheach other, one skilled in the art will appreciate that many of thesefeatures can be provided independently of other features. Accordingly,this description of the invention is set forth without any loss ofgenerality to, and without imposing limitations upon, the invention.

Overall Intercom System and Integration with Legacy Functionality

FIG. 1A shows an overall view of an exemplary intercom station 108within an exemplary legacy intercom system 100, in accordance with someembodiments of the invention. The legacy intercom system 100 controlsthe unlocking of a door 114 (e.g., the lobby door) or a gate of abuilding 118 that comprises one or more units. In some embodiments,these one or more units are apartment units. In some embodiments, thebuilding includes both a gate and a door, multiple doors, a combinationof gates and doors, where an outside guest must pass through severalsuch barriers to gain entry into the building. The intercom station 108(e.g., a “Buzr device”) is located in a user's apartment unit 120. Theintercom station 108 as disclosed replaces, modifies, or supplements aconventional apartment unit intercom station and is compatible withexisting legacy hardware and wiring. In some embodiments, the intercomstation 108 is battery-powered so that its operation does not depend onan external power source.

An intercom central unit (ICU) 110 acts as a central processing unit forthe intercom system 100; it is connected via an intercom network 122 tothe intercom station 108, a lobby panel 112, and a door lock 116. Thelobby panel 112 is near the door, accessible to a person (e.g., a guest)seeking entry via the door 114. The door lock 116 is anelectromechanical device (e.g., a solenoid bolt) that locks or unlocksthe door 114 in response to a signal from the ICU 110. In someembodiments, the intercom network 122 is wired. In other embodiments,one or more connections within the intercom network 122 is wireless(e.g., Wi-Fi, Bluetooth). In some embodiments, the intercom system 100further comprises a system backend 102, which comprises a server 124 anda data storage medium 126. The system backend 102 enables the intercomstation 108 to interact with a mobile device 104 running a mobileapplication 128 (“mobile app” or simply “app”) directed to the intercomstation 108. In some embodiments, the mobile app 128 is accessible by auser 106 who manages the intercom station 108 or a guest seeking entryinto the building 118. In some embodiments, the system backend 102connects to the intercom station 108 and to the mobile device 104 viathe Internet 130. In some embodiments, the intercom station 108 connectsto the Internet 130 via a wireless access point 132 in the building 118or in the user's apartment unit 120 specifically. In other embodiments,the intercom station 108 connects to the Internet 130 via a wiredconnection (e.g., an Ethernet cable). In some embodiments, instead of orin addition to a system backend 102, the intercom system 100 furthercomprises a local server or a local device. In such embodiments, thelocal server or a local device may perform similar features as describedherein regarding the system backend 102.

The lobby panel 112 performs several functions for interfacing with aguest seeking entry into the building 118 via the door 114. In someembodiments, the lobby panel 112 comprises a set of doorbells 134, witheach doorbell corresponding to an apartment unit in the building. Insome embodiments, the lobby panel 112 comprises a microphone 136configured to receive a guest's voice and an audio speaker configured togenerate sound to be heard by the guest. In some embodiments, themicrophone 136 and the audio speaker are the same electronic device. Theintercom station 108 performs several functions for interfacing with auser 106, the system backend 102, and the mobile app 128. In someembodiments, the intercom station 108 comprises a “door” (or “unlock”)button. In some embodiments, the intercom station 108 further comprisesa station audio emission subsystem configured to emit a first audiosignal and a station audio reception subsystem configured to receive asecond audio signal. In some embodiments, the station audio emissionsubsystem is an audio speaker, the first audio signal is a sound (e.g.,a sound to be heard by the user), the station audio reception subsystemis a microphone, and the second audio signal is a second (e.g., theuser's voice). In other embodiments, the station audio emissionsubsystem and the station audio reception subsystem are electronicsystems that relay audio information to and from a system backend, alocal service, or a local device. In such embodiments, the first audiosignal and the second audio signal are digital signals.

In some embodiments, the intercom station 108 further comprises a“listen” feature configured to activate the microphone of the lobbypanel and to activate the speaker of the intercom station 108, and a“talk” feature configured to activate the microphone of the intercomstation 108 and to activate the speaker of the lobby panel 134. In someembodiments, intercom station 108 does not include a microphoneconfigured to receive a user's voice nor an audio speaker configured togenerate sound to be heard by the user, in which case all audiocommunication is relayed between the lobby panel and a system backend, alocal service, or a local device. In such embodiments, the “talk”feature may not activate a microphone of the intercom station 108, butmay instead initiate communication with a guest via other means (e.g.,the user speaks into a mobile device, the backend sends a pre-recordedmessage); and the “listen” feature may not activate a speaker of theintercom station 108, but may instead initiate storing or relaying theaudio signal from the speaker of the lobby panel 134.

In some embodiments, the “listen” feature is a “listen” button, and the“talk” feature is a “talk” button. In some embodiments, the “talk”feature and the “listen” feature are implemented as a single button thatturns on (or off) the two-way audio system. In some embodiments, the“talk” feature and the “listen” feature are implemented as a handset atone or both ends, which, after being picked up, allows the user 106 andthe guest to speak to one another as if speaking over a telephone. Forconvenience, the legacy intercom station and/or the intercom station maybe described herein with reference to a “listen” button and a “talk”button, but alternative embodiments that include implementing the“listen” feature and the “talk” feature in other ways would be apparentto those skilled in the art.

In some embodiments, the lobby panel 112 includes a video camera or astill camera, which permits a user to see the guest on a video screen onor near the intercom station 108. In some embodiments, the video camerais always on. In some embodiments, the video camera may be activated bynearby motion or other stimuli. In some embodiments, the video cameramay be activated by a “watch” feature on the intercom station 108. Inother embodiments, the video camera may be activated whenever the“listen” or “talk features are activated, e.g., buttons are pressed orheld down.

In some embodiments, the door 114 may be manually unlocked via aphysical key. In some embodiments, the door 114 is by default lockedwhenever the door 114 is closed. The intercom station 108 enables aguest to unlock the door 114 without a physical key for the door 114 noranother person personally opening the door 114 from the other side. Whena guest outside the door 114 requests unlocking the door 114, he or sheactivates (“rings”) a doorbell 134 on the lobby panel 112 thatcorresponds to the guest's target apartment unit. When the doorbell 134is activated, the lobby panel 112 sends the unlocking request as asignal to the ICU 110, which relays it to the intercom station 108 inthe target apartment unit. In some embodiments, the intercom station 108notifies the user 106 that an unlock request has been sent. Thenotification may be, for example, a doorbell ring that is audiblethroughout the apartment unit 120 to alert the user 106. In otherembodiments, the notification is a visual cue (e.g., flashing light),which may be helpful for users with auditory disabilities. The user 106may approve of the unlocking request by activating the “door” button onthe intercom station 108, which sends the unlocking approval as a signalto the ICU 110, which sends a request to the door lock 116 to unlock thedoor 114. As typical door locks generate a buzzing sound when the door114 is unlocked, this process is colloquially referred to as “buzzing” aperson into a building. In some embodiments, the “door” button supportsthe unlocking of the door 114 without an unlock request sent by a guest.

In some embodiments, the intercom system 108 enables the user 106 andthe guest to speak to each other via audio conferencing. In someembodiments, the user 106 and the guest interaction is further enhancedwith video conferencing. These features are useful for the user toconfirm the identity of the guest before buzzing the guest into thebuilding 118, for example. When the intercom station 108 notifies theuser 106 that an unlock request has been sent, the user 106 has theoption of activating the microphone of the intercom station 108 and thespeaker of the lobby panel 112, but not the speaker of the intercomstation 108 nor the microphone of the lobby panel 112, by pressing andholding down the “talk” button. Once these devices are activated, theuser 106 may speak to the guest at the lobby. When the user 106 releasesthe “talk” button, the microphone of the intercom station 108 and thespeaker of the lobby panel 112 are deactivated, and the user 106 may nolonger speak to the guest. In some embodiments, the intercom system 108enables the user 106 to passively listen to sounds in the lobby,including the guest's voice, by pressing and holding down the “listen”button, which activates the microphone of the lobby panel 112 and thespeaker of the intercom station 108, but not the speaker of the lobbypanel 112 nor the microphone of the intercom station 108. Once thesedevices are activated, the guest in the lobby may speak to the user 106.When the user 106 releases the “listen” button, the microphone 136 ofthe lobby panel 112 and the speaker of the intercom station 108 aredeactivated, and guest user may no longer speak to the user 106. In someembodiments, multiple apartment units may simultaneously activate the“listen” function without interference. By alternately pressing the“talk” and the “listen” buttons, the user 106 may conduct a conversationwith a guest at the lobby.

In alternative embodiments, the intercom system 108 enables the user 106and the guest to speak to each other via audio conferencing without theneed of “talk” or “listen” buttons by including a handset at one or bothends, which, after being picked up, allows the user 106 and the guest tospeak to one another as if speaking over a telephone.

In some embodiments, whenever the “talk” or “listen” buttons arepressed, held, or released, a signal encapsulating the request is sentfrom the intercom station 108 to the ICU 110, which routes the signal tothe lobby panel 112 to activate or deactivate the appropriate devices.Whenever audio signal is transmitted (e.g., the user holds down the“talk” button while speaking into the intercom station microphone, theuser 106 holds down the “listen” button while the guest is speaking intothe lobby panel microphone 136), the signal is routed between theintercom station 108 and the lobby panel 112 via the ICU 110.

In some embodiments, the intercom station 108 further enables the user106 to perform the doorbell ring notification, buzz, talk, and listenfunctions remotely through the mobile app 128. In some embodiments, theintercom system 100 includes features such as the use of a guest mobileapp, virtual keys for guests to enable the unlocking of the door 114when the user 106 is not present, geofencing, the automatic unlocking ofthe door 114 upon request, and the unlocking of the door 114 via theintercom station 108 or the mobile app 128 without an unlock requestsent by a guest. Details of these features are provided in thisdisclosure.

The intercom system 100 comprises a preexisting extra-unit intercomsystem, which is the set of components outside the apartment unit thattypical legacy intercom systems have. For example, the preexistingextra-unit intercom system comprises a lobby panel (e.g., front doordoorbell panel), a plurality of intercom station interfaces, and a setof wiring corresponding to the plurality of intercom station interfaces.In some embodiments, such as when interfacing with analog intercomsystems, the extra-unit intercom further comprises an intercomamplifier. In some embodiments, such as when interfacing with digitalintercom systems, the extra-unit intercom further comprises a controlunit. At each apartment unit, the set of wiring is accessible via one ormore holes in the apartment unit's wall. The set of wiring enables aninstalled intercom station to interact with the preexisting extra-unitintercom system. In some embodiments, a mount plate with organized wiresprovides a mechanically robust and electrically stable means forinstalling the intercom station (e.g., “physical device”, “Buzr”, “BuzrDevice”, or “Buzr Pro Device”) into the apartment unit by connecting theintercom station 108 to the set of wiring via the mount plate. In someembodiments, the intercom station disclosed herein is installedalongside a pre-existing intercom station without replacing it.

FIG. 1B shows a schematic 101 of an exemplary intercom station 108interacting with a backend 140, a mobile application 128, and otherservices 138, in accordance with some embodiments of the invention. Abackend cloud-computing service (CCS) 140, such as Amazon Web Services(AWS), interfaces with the intercom station 108 and the mobile app 128,as described earlier with reference to FIG. 1A. In some embodiments, theAWS backend cloud-computing service 140 includes a simple notificationservice 144, an IoT core 158, one or more Lambda functions 152, DynamoDB150 (device database, history database, virtual keys database), one ormore API functions 156, and/or Cognito 148 (a user database). Featuresand operations of these components are readily apparent to those skilledin the art. The backend CCS interacts with several other services. Insome embodiments, such interactions include the simple notificationservice 144 interfacing with Firebase Cloud Messaging 142 to enableAndroid push notification processing and with Apple Notifications 146 toenable iOS push notification processing, and the mobile app 128interfacing with Firebase Crashlytics 154.

In some embodiments, the backend cloud-computing service 140 maintains atime-stamped record of its input and output, such as unlock requests byguests, unlock approvals granted by users, conversations between usersand guests, sounds from the lobby, and so on. This record is retrievableby the user via the mobile app 128 or a website.

In some embodiments, the intercom station 108 and/or backendcloud-computing service 140 may integrate with third-party services,including home hosting services (e.g., Airbnb), delivery providers(e.g., DoorDash), smart home systems (e.g., Amazon Alexa, Google Home).This may be implemented by providing the third-party service'srepresentative with a virtual key, by maintaining a direct integrationwith the third-party service's backend, or through conversing with acall center agent at the front door of the building.

FIG. 2A shows an isometric view of an exemplary intercom station 200with a trim plate 202, in accordance with one embodiment of theinvention. The example shown has three buttons on the front face: a talkbutton 204, a listen button 206, and a door button 208.

FIG. 2B shows a front view of an exemplary intercom station 200 with atrim plate 202, in accordance with one embodiment of the invention.

Intercom Station Installation

FIGS. 3A, 3B, 3C, 3D, 3E, 3F, 3G, 3H, 3J, 3K, and 3L show variouschronological stages of an old, pre-existing intercom station beingreplaced with a new intercom station (“device”). The device is adaptableto a wide range of legacy intercom systems, causes no harm nor impact tothe legacy system during installation, maintains original in-homefunctionality without an internet connection or battery, and isinsulated from the legacy system's varying voltages. The device isdesigned to be straightforward and safe to install for non-specialistconsumers (e.g., less than 50 minutes for a typical user) through theuse of a universal mounting plate to re-orient wiring from the existingsystem to match the device and align with existing mount screw holes. Insome embodiments, the installation covers a legacy intercom systemfootprint through the use of an optional trim plate to hide anyblemishes on the apartment wall. In some embodiments, the intercomstation disclosed herein is installed alongside a pre-existing intercomstation without replacing it.

FIG. 3A shows views of an exemplary apartment unit 300 before and afterinstalling an exemplary intercom station, in accordance with someembodiments of the invention. Traditional intercom stations 303typically do not require any Internet connection nor any connection toother device. In contrast, the intercom station 305 as disclosed hereinmay connect to the Internet via, for example, a wireless connection. Itmay also connect to a managed backend system, a local device, or a localserver.

FIG. 3B shows an exemplary pre-existing intercom station 302 installedin the wall of an apartment unit, in accordance with some embodiments ofthe invention. In some embodiments, the pre-existing intercom station302 has a microphone, a speaker, a talk button 306, a listen button 308,and/or an unlock (“door”) button 310. In some embodiments, thepre-existing intercom station 302 includes a handset, which allows auser to speak to a guest telephonically. In some embodiments, thehandset is operated with the talk button and the listen button. In someembodiments, the handset is operated with an activate button thatperforms both the talk feature and the listen feature of the talk buttonand of the listen button, respectively. In other embodiments, thehandset is operated without the talk button or the listen button. Insome embodiments, the pre-existing intercom station 302 includes a videoscreen that may display the output from a video camera at or near thelobby panel.

FIG. 3C shows an exemplary pre-existing intercom station 302 beingunscrewed 312 from the wall of an apartment unit, in accordance withsome embodiments of the invention. As the pre-existing intercom station302 is being removed, its wires 314 that connect it with the rest of theintercom system are exposed.

FIG. 3D shows an exemplary pre-existing intercom station 302 with wireslabelled 316, in accordance with some embodiments of the invention. Bylabelling the wires 316 with their appropriate function, they may belater connected to the correct nodes of the new intercom station. Insome embodiments, the labels are based on previous connectivity, and notnecessarily based on functionality because there is no standard forwiring in legacy systems.

FIG. 3E shows an exemplary pre-existing intercom station 302 with wiresdisconnected 318, in accordance with some embodiments of the invention.At this point, the pre-existing intercom station 302 is uninstalled andmay be used for other purposes, such as being installed into anotherapartment unit or recycled.

FIG. 3F shows a trim plate 320 of an exemplary intercom station beingaligned with the wall of an apartment unit, in accordance with someembodiments of the invention. In some embodiments, the trim plate 320comprises a hole 322 through which the wires 316 may be drawn. In someembodiments, the trim plate 320 comprises mounting holes 324, 326through which screws or nails 328, 330 may be used to secure the trimplate 320 to the wall. In addition to securing the intercom station tothe wall, another use of the trim plate 320 is to hide any blemishes onthe apartment wall.

FIG. 3G shows a trim plate 320 of an exemplary intercom stationinstalled into the wall of an apartment unit, in accordance with someembodiments of the invention. In the embodiment shown, two screws 328,330 secure the trim plate 320 to the wall.

FIG. 3H shows a mounting plate 332 of an exemplary intercom stationbeing aligned with a trim plate 320 mounted onto the wall of anapartment unit, in accordance with some embodiments of the invention. Insome embodiments, the mounting plate 332 of the intercom stationcomprises holes 338 that align with corresponding holes 336 in the trimplate 320. Screws or nails may be used to secure the mounting plate 332of the intercom station to the trim plate 320 via the holes 338. In someembodiments, there is a hole 334 through which the wires as described inFIG. 3D are drawn and accessed.

FIG. 3J shows a mounting plate 332 of an exemplary intercom stationinstalled into a trim plate 320 mounted onto the wall of an apartmentunit, in accordance with some embodiments of the invention. In someembodiments, the mounting plate 332 is directly mounted onto the wall ofthe apartment unit without the use of an intermediate trim plate. Thewires 316, which had been labelled by their appropriate functions, arethen attached to their respective electrical nodes 340 in the mountingplate 332 of the intercom station so that the intercom station isconnected to the building portion of the intercom system. Variouselectronic attachments are available to those skilled in the art. Insome embodiments, the electrical nodes access a printed circuit board(PCB) embedded in the mounting plate 332.

FIG. 3K shows an enclosure of an exemplary intercom station 304 beingaligned with a mounting plate 332, in accordance with some embodimentsof the invention. In some embodiments, the enclosure of the intercomstation 304 comprises “talk” 342, “listen” 344, and “door” buttons 346that enable the user to talk to a guest at the lobby, enable the user tolisten to sounds in the lobby, and enable the user to unlock the lobbydoor, respectively. In some embodiments, the enclosure of the intercomstation 304 comprises a microphone and a speaker to perform the soundsensing and the sound emitting features of the “talk” and “listen”functions. In some embodiments, electrical connections between themounting plate 332 and the enclosure of the intercom station 304 connectthe electronic components for the “talk” 342, “listen” 344, and “door”buttons 346, the microphone, and the speaker from the enclosure to themounting plate 332, ultimately connecting those components to the restof the intercom system. Various electronic attachments are available tothose skilled in the art.

FIG. 3L shows an enclosure of an exemplary intercom station 304installed onto a mounting plate 332, in accordance with some embodimentsof the invention. At this point, the installation of the intercomstation 304 is complete, and it is ready to interface with the rest ofthe intercom system and the user.

Schematics and Electronics

FIG. 4A shows a first-level functional block diagram 400 of the varioussubsystem components of the exemplary intercom station, in accordancewith some embodiments of the invention. As depicted in greater detail inFIGS. 4C and 4D, the intercom station adapts to existing intercomsystems using isolation circuitry to insulate the intercom station fromthe building's wiring, which increases compatibility across multiplesystems and ensures that other building residents are not negativelyaffected by the intercom station being installed on a shared system. Theintercom station maintains legacy functionality by maintaining buttons,a speaker, and a microphone in an alternate subcircuit so that in theevent of power loss or Internet loss, the user is still able to heartheir doorbell ring and interact with the front door while present inthe apartment unit. In some embodiments, the hardware and software ofthe intercom station may be implemented in accordance with the diagramsshown and discussed in reference to FIGS. 16 and 17 .

The analog legacy wiring interface 406 for a legacy intercom systeminterfaces with the legacy intercom system by relaying audio signals,door unlock requests, door unlock approvals, lobby speaker activationand deactivation requests, and/or lobby microphone activation anddeactivation requests. In embodiments where the lobby panel 112 includesa video camera or a still camera, which permits a user to see the gueston a video screen on or near the intercom station 108, the analog legacywiring interface 406 also relays a video feed. In some embodiments, theanalog legacy wiring interface 406 may be implemented on a mount platePCB and is represented in greater detail in FIGS. 4C and 4D; and theaudio input-output (I/O) circuit 402, processor (e.g., microcontrollerunit) config circuit (MCU config) 404, audio config 408, and powermanagement circuit 410 are all on a main circuit board (along withinterface headers that interact with the mount plate PCB) represented inFIG. 5A, a block diagram of the main circuit board. The universal relayand audio isolation subsystems in the analog legacy wiring interface 406for the legacy intercom processes such information, exchanges audiosignals with the audio input-output (I/O) circuit 402, and exchangesnon-audio information with the processor config circuit 404, whichcontrols the intercom station. In some embodiments, the processor configcircuit 404 is a microcontroller unit config circuit (MCU config) 404.For convenience, this disclosure may describe “microcontroller unitconfig circuits (MCU config)” in particular, but the teachings anddiscussion may apply more generally to “processor config circuits” aswell, as referenced in FIGS. 16 and 17 . The MCU config 404 use acommunication protocol (e.g., MQTT via Wi-Fi) to transmit messages tothe managed backend system, a local device, or a local server. The audioinput-output (I/O) circuit 402 processes audio signals, and exchangesaudio signals with the MCU config 404.

The power management circuit 410 includes regulators and voltageprotection circuitry to allow for the various subsystems to operate attheir respective required voltages. In some embodiments, a globalvoltage source of 6 V (e.g., provided by four AA batteries) and a globalvoltage source of 5 V (e.g., provided by a USB cable) are converted to3.3 V, 2.5 V, and 15 V when needed. In some embodiments, the intercomstation is powered by a standard battery or by a plurality of standardbatteries (e.g., four AA batteries) with typical usage convenientlyrequiring infrequent battery replacement or recharging. In someembodiments, greater than 12 months of battery life may be achieved byusing sleep modes on the MCU 404, even while maintaining a steadyconnection to the Internet at all times so that a guest does not need towait for the intercom station to regain Internet connection. In someembodiments, the intercom station may also be externally powered via acable (e.g., micro-USB).

Audio config 408 includes both the isolation circuitry needed toaccommodate tone detection 540 functionality as well as theconfiguration circuitry needed to support the station speaker. In someembodiments, the regulator that boosts 6 V to 15 V (as referenced above)and the amplifier that outputs to the station speaker are located inthis schematic sheet as well.

FIG. 4B shows a second-level functional block diagram 420 of the varioussubsystem components of the exemplary intercom station, in accordancewith some embodiments of the invention. To develop the intercom station,much experimentation was conducted on a wide range of legacy intercomsystems in order to understand their common characteristics and to avoidengineering a universal intercom system that works only for a specificlegacy system. A circuit (“Buzr Lite”) that is able to detect doorbellrings and alert the user in a mobile phone application was achievedthrough opto-isolation methods, which required much trial and error, asthe signal that is sent through the line is very variable betweensystems and may trigger multiple erroneous doorbell ring notificationsif not tuned correctly. In some embodiments, a push notification shouldbe received within a brief period (e.g., 5 seconds) of someone pressingthe doorbell at the front of the building. Additionally, only one pushnotification will be received. In some embodiments, oscillations in thedoorbell or continuous doorbell presses will not trigger additionalnotifications within a refractory period (e.g., 90 seconds) of the firstnotification.

To achieve universal wiring compatibility across a wide variety oflegacy intercom systems, sourced documentation from the most commonsystems were studied. A universal relay system is then devised, assumingthat signals are properly isolated in the next stage of the intercomstation's circuitry. To understand how legacy intercom systemscommunicate audio, oscilloscope readings of the various systems underinteraction were recorded and studied. Exemplary waveforms resultingfrom these experiments are discussed herein with reference to FIGS. 6A,6B, 6C, and 6D. By compiling waveforms across many systems, universalcircuitry that would work across each of these systems is devised.

Generally, all systems share the same four core operations of talking,listening, doorbell ringing, and buzzing a door open. Accordingly, thereare only a limited number of wiring configurations to achieve this.However, there is no standard as to how these connections are made oreven how many wires there are. The major configurations are digital oranalog and either 2, 4, or 5 wires (although 3 & 6 wire systems exist aswell). Three exemplary legacy systems are the 2-wire digital Aiphone GTsystem, the analog PK543A (which can accommodate 3-wire stations, 4-wirestations, or 5-wire stations), and the analog AF1000 (a 6-wire station).

In some embodiments, the intercom station comprises isolation circuitsand other electronics that perform signal processing and filteringoperations (e.g., hardware-based or software-based digital signalprocessing) for the management of various audio functions 412. Theintercom station processes audio for wireless transmission by extractingelectrical signals through isolation circuits and pre-filtering audiovia an analog-to-digital converter (ADC) and transmitting the encodedaudio to the mobile app for listening by the user. In some embodiments,the ADC is directly on a processor. In some embodiments, the processoris a microcontroller unit (MCU). For convenience, this disclosure maydescribe “microcontroller units (MCU)” in particular, but the teachingsand discussion may apply more generally to “processors” as well, asreferenced in FIGS. 16 and 17 . In some embodiments, the ADC is a deviceexternal to a processor or other circuits. In some embodiments, theintercom station further includes an audio codec that interfaces withthe ADC. The intercom station also processes audio for audible output byreceiving audio signal via the mobile app and transmitting the audiosignal to the intercom station. In some embodiments, the audio signal isfirst processed through a digital-to-analog converter (DAC) before beingfed into a filter, whereas in alternative embodiments, the audio signalis fed directly into a filter. The filter outputs to a decoder and iseventually outputted to the front door speaker.

The audio input-output (I/O) circuit 412 performs all audio transmissionand filtering functions related to legacy communication as well as thestation microphone. These functions share a common operational amplifierbank 422. The line input buffer 414 extracts audio from the legacysystem to be used by the intercom station via the processor's 426 ADC.In some embodiments, this process requires isolation (such as via atransformer) and amplification to allow the incoming signals to beinterpretable by a typical processor ADC, which would otherwise bechallenging due to the low amplitude of incoming signals compared to thesensitivity of the ADC. This need for amplification is highlighted inFIG. 6C. The line output buffer (or line output driver) 416 performs theopposite operation as the line input buffer 414 by taking output from adigital-to-analog converter (DAC), running the result through isolation(such as via a transformer), and finally attenuating the signal so thatit is once again within the expected amplitude range of the legacysystem. In some embodiments, microphone amplifier 418 is amicroelectromechanical (MEMS) microphone whose signal is passed throughan operational amplifier circuit before being fed into the processor426. In some embodiments, the processor is a microcontroller unit (MCU)426. In some embodiments, the operational amplifier bank 422 containsshutdown functionality for power saving purposes, and configures variousvoltage dividers to adapt the general-purpose input/output (GPIO)voltage of 3.3 V to the expected shutdown (SHDN) voltage of 2.5 V.

The microcontroller unit config circuit (MCU config) 424 is the overallconfiguration of the microcontroller unit (MCU) 426 and its associatedbutton connectors 428 and programming headers 430. In some embodiments,the microcontroller unit (MCU) 426 includes pin/port connectivity,power, and antenna connectivity. In some embodiments, the buttonconnectors 428 are the button inputs for the intercom station's userinput interfacing, such as the “talk”, “listen”, “buzz”, “device reset”,and “WiFi reset” features. In some embodiments, the programming headers430 are optional programming headers for UART & SW/Think interfaces,which enable rapid prototyping and board programming but may be removedfor mass production. In some embodiments, the microcontroller unit (MCU)426 is configured to interact with and control a station audio emissionsubsystem and a station audio reception subsystem, as described withreference to FIG. 1A.

As described above, in some embodiments, the analog legacy wiringinterface 432 may be implemented on a mount plate PCB and is representedin greater detail in FIGS. 4C and 4D. The analog legacy wiring interface432 contains circuitry needed for compatibility with analog legacyintercom systems. Other legacy wiring interface designs may beimplemented for compatibility with digital legacy intercom systems. Theanalog legacy wiring interface 432 contains isolation circuitry 434,which are isolators used to extract incoming control signals from themicrocontroller unit config circuit (MCU config) 424 before passing thesignals to the relays to control the legacy system. In some embodiments,this subcircuit is technically deprecated by the embodiment depicted inFIG. 4D when this subsystem is combined with the mode configurationcircuit 436, which is the signal routing and relay control circuitrythat allows the intercom station to manipulate the legacy system. Forexample, the mode configuration circuit 436 allows the intercom stationto buzz the legacy system and opens the line in or line out circuits sothat the intercom station may interact with the audio signals via theaudio input-output (I/O) circuit 412.

Audio config 438 includes both the isolation circuitry needed toaccommodate tone detection 440 functionality as well as the stationspeaker configuration circuitry 442. The tone detection circuit 440detects and extracts the oscillation waveform shown in FIGS. 6B and 6C,and is discussed in greater detail with reference to FIG. 5C.

FIG. 4C shows a functional block diagram 450 of the exemplary intercomstation with separate universal relay and audio isolation subsystems, inaccordance with some embodiments of the invention. This embodiment maybe used in conjunction with the second-level functional block diagram420 as depicted in FIG. 4B and may be implemented in accordance with thecircuit diagrams shown in FIGS. 5D (universal relay) and 5E (audioisolation). In some embodiments, a subsystem may reside on a separatemounting PCB. The legacy system wiring 454 includes pre-existing wiresfrom the legacy system. In some embodiments, the legacy system wiring454 may be connected to the intercom station via B2W connectors.

Relay control signals 446 are sent from the microcontroller unit configcircuit (MCU config) 424 via headers that interface with the main boardto the isolation circuitry for analog signal extraction. The isolationcircuitry protects the microcontroller unit config circuit (MCU config)from the larger signals in the legacy system as well as preventsinterference in the legacy system. Headers 448 provide connectivity tothe main PCB. An analog isolation circuit 451 generates a barrierbetween the relays/legacy system and the MCU control signals. In someembodiments, the analog isolation circuit 451 is implemented usingtechniques such as opto-isolation, RF isolation, and TTL(transistor-transistor logic) MOSFET circuits. In some embodiments, itis implemented using MOS-relays, which combines the analog isolationcircuit 451 and the analog mode config circuit 456 as discussed withreference to FIG. 4D.

Audio signals 452 are passed through the mount plate because allisolation and audio processing are performed on the main board. Thefunctionality of the mount plate with reference to audio signals 452 isto connect to the proper line of the legacy intercom system when audiois needed to prevent unintended interference or audio artifacts to thelegacy system when the intercom station is not attempting to communicateon the talk or listen lines. This is also manifested in relays B and Cin FIG. 5D.

Signals 458 are sent from the analog isolation circuit 451 to controlthe relays in the analog mode config circuit 456. After isolation ofcontrol signals, the relays extract the signals 458 from the legacyintercom system. In some embodiments, the signals 458 may actuatecommands directly for non-audio signals, such as a door buzz. Non-audiosignals 460 directly control the legacy intercom system. For example, anon-audio signal 460 may engage relay D in FIG. 5D to trigger a doorbuzz.

FIG. 4D shows a functional block diagram 470 of the exemplary intercomstation with combined universal relay and audio isolation subsystems, inaccordance with some embodiments of the invention. This embodiment maybe used in conjunction with the second-level functional block diagram420 as depicted in FIG. 4B and may be implemented in accordance with thecircuit diagram shown in FIG. 5F. In some embodiments, a subsystem mayreside on a separate mounting PCB. The operation of FIG. 4D parallelsthat of FIG. 4C in a manner that is readily apparent to those skilled inthe art. Signals 468 are a combination of relay control signals 446 andsignals 458. Analog mode config circuit 472 includes a major improvementin terms of signal integrity and BOM cost by combining analog isolationcircuit 451 and analog mode config circuit 456 by using MOS relays.These components automatically perform both the isolation functionalityand the relay/switching functionality to properly interface with andcontrol the legacy intercom system wiring.

FIG. 5A shows an exemplary functional block diagram 510 of the variouselectrical components of the exemplary intercom station, in accordancewith some embodiments of the invention. The block diagram 510 shows theconnections between the various subsystem components shown in thefirst-level and second-level functional block diagrams of FIGS. 4A and4B. The analog legacy wiring interface 511 for a legacy intercom systemreceives an audio signal (“AUDIO_TO_STATION”) from the legacy intercomsystem. In some embodiments, this audio signal is a message from themicrophone of the lobby panel to be relayed to the user of the intercomstation. The universal relay and audio isolation subsystems in theanalog legacy wiring interface 511 for the legacy intercom processes theaudio signal (“AUDIO_TO_STATION”) and transmits another audio signal(“LINE_IN_BLD_REF”) to a line input buffer of an audio input-output(I/O) circuit 512. Similarly, the analog legacy wiring interface 511 forthe legacy intercom receives an audio signal (“LINE_OUT_BLD_REF”) from aline output driver of the audio input-output (I/O) circuit 512. In someembodiments, this audio signal is a message from the user of theintercom station to be relayed to the speaker of the lobby panel. Theuniversal relay and audio isolation subsystems in the analog legacywiring interface 511 for the legacy intercom processes the audio signal(“LINE_OUT_BLD_REF”) and transmits another audio signal(“AUDIO_FM_STATION”) to the legacy intercom system.

The line input buffer of the audio input-output (I/O) circuit 512receives the audio signal (“LINE_IN_BLD_REF”) from the analog legacywiring interface 511 for a legacy intercom system and transmits an audiosignal (“LINE_IN_BUF”) to a processor 513. In some embodiments, theprocessor 513 is a microcontroller unit (MCU) 513. The line outputdriver of the audio input-output (I/O) circuit 512 receives an audiosignal (“DAC_OUT”) from the microcontroller unit (MCU) 513 and transmitsan audio signal (“LINE_OUT_BLD_REF”) to the analog legacy wiringinterface 511 for the legacy intercom system.

The microphone input buffer (“MIC_IN_BUF”) of the audio input-output(I/O) circuit 512 is the output from the operational amplifier circuitthat corresponds to a driver being used for the on-boardmicroelectromechanical (MEMS) microphone. Although alternative solutionsexist for configuring a microphone within a product, advances in MEMStechnology have brought such microphones to the cutting edge of theoverall IoT industry. Specific considerations were taken on themechanical side to ensure that proper vibration dampening and soundchannels were included. The microphone input buffer (“MIC_IN_BUF”) lineis fed into one of the two internal microcontroller unit (MCU) ADCs.

The enable audio line (“EN_AUDIO_IO”) is one of the two shutdown/enablelines for the operational amplifier bank 422. It controls the voltagebuffer (e.g., the operational amplifier) in the line input buffer andthe operational amplifier of the microphone. The enable output line(“EN_OUT_AMP”) is the other one of the two shutdown/enable lines for theoperational amplifier bank 422. It controls the voltage buffer (e.g.,the operational amplifier) in the line output driver.

FIG. 5B shows an exemplary circuit diagram of the line input buffer 520and line output driver 530 of the exemplary intercom station, inaccordance with some embodiments of the invention. The line input buffer520 and line output driver 530 may together form an audio input-output(I/O) circuit 512 configured to process audio signals for analogsystems. In some embodiments, as shown in the circuit diagram, an audioline ground 509 (“LINE_GND”) is a common line from the legacy intercomsystem, and a “GND” is an electrical ground. The line input buffer 520receives as input a first input signal 521 (“LINE_IN_BLD_REF”) from thewiring interface 511 for a legacy intercom system, which represents anaudio signal. In some embodiments, the line input buffer 520 includes afirst electrostatic discharge (ESD) and transient protection subcircuit522A, 522B that is configured to receive the first input signal. In someembodiments, the audio line ground 509 (“LINE_GND”) is coupled to thefirst electrostatic discharge (ESD) and transient protection subcircuit522A, 522B. In other embodiments, the line input buffer 520 does notinclude an electrostatic discharge (ESD) and transient protectionsubcircuit. In some embodiments, the first electrostatic discharge (ESD)and transient protection subcircuit includes a first ESD resistor 522A(“R1”, e.g., 22Ω) and a first transient-voltage-suppression (TVS) diode522B (“D1”). A value of 22Ω for the first ESD resistor 522A is asuitable starting value for signal integrity, as using a capacitor mayslow down the signal and using a higher resistance would result in animpedance of the signal as opposed to merely smoothing the signal, thedesired result. The 22Ω value may be increased after ESD/signalintegrity experiments determine that additional smoothing is required.For example, previous experiments have already determined that theseries resistances of the transmission line in the tone detectioncircuit should be approximately 200Ω due to the type of signal input(see FIG. 6B) that is expected to be observed in the input side of thatcircuit. Note that many ESD and signal integrity methods are known tothose skilled in the art and may easily be substituted here or evenremoved entirely if providing protection for the circuit components isunnecessary.

The line input buffer 520 further includes a first galvanic isolator andvoltage scaler subcircuit 524, 525A, 525B, 525C, 525D. In someembodiments, the audio line ground 509 (“LINE_GND”) is coupled to thefirst galvanic isolator and voltage scaler subcircuit 524, 525A, 525B,525C, 525D. In embodiments of the line input buffer 520 that include afirst electrostatic discharge (ESD) and transient protection subcircuit522A, 522B, the first galvanic isolator and voltage scaler subcircuit524, 525A, 525B, 525C, 525D is coupled to the first electrostaticdischarge (ESD) and transient protection subcircuit 522A, 522B. Inembodiments of the line input buffer 520 that do not include anelectrostatic discharge (ESD) and transient protection subcircuit, thefirst galvanic isolator and voltage scaler subcircuit 524, 525A, 525B,525C, 525D is configured to receive the first input signal. In someembodiments, the first galvanic isolator and voltage scaler subcircuit524, 525A, 525B, 525C, 525D includes a first transformer 524 (“T1”). Insome such embodiments, the first transformer 524 (“T1”) performs bothgalvanic isolation and voltage scaling functions. In other embodiments,the first galvanic isolator and voltage scaler subcircuit 524, 525A,525B, 525C, 525D includes a first transformer 524 (“T1”) and a firstvoltage scaler 525A, 525B, 525C, 525D coupled to the first transformer524 (“T1”). In some embodiments, the audio line ground 509 (“LINE_GND”)is coupled to the first transformer 524 (“T1”). In some embodiments, noamplification nor attenuation from the first transformer 524 is needed,so the first transformer 524 is 1:1. In other embodiments, the firsttransformer 524 is configured to have another ratio of primary andsecondary coils to achieve the attenuation or amplification effects ofvoltage scaling. In still other embodiments, the first galvanic isolatorand voltage scaler subcircuit 524, 525A, 525B, 525C, 525D includes anopto-isolator. In some such embodiments involving the opto-isolator orother isolation component, the voltage scaling is approximately 1. Notethat this scale factor applies only to the isolation component, not tothe entire first galvanic isolator and voltage scaler subcircuit 524,525A, 525B, 525C, 525D, as additional scaling and/or attenuation may berequired.

In some embodiments, the first voltage scaler 525A, 525B, 525C, 525Dincludes a first voltage divider 525A, 525B coupled to the firsttransformer 524 (“T1”). In some embodiments, the first voltage divider525A, 525B includes a plurality of resistors 525A, 525B (“R2” and “R3”).In some embodiments, the first voltage divider 525A, 525B generates aratio of approximately 50% (e.g., “R2” and “R3” are both 1 kΩ); i.e., ithalves the output of the first transformer 524 so that the signal is inthe appropriate range for the MCU 513. The 50% ratio permits the lineinput buffer 520 to obtain the signals for a wide variety of legacyintercom systems. In some embodiments, the first voltage scaler 525A,525B, 525C, 525D further includes a second voltage divider 525C, 525Dcoupled to the first voltage divider 525A, 525B, where the bottom sideof the output of the first transformer 524 is connected to the secondvoltage divider 525C, 525D. In some embodiments, the second voltagedivider 525C, 525D includes a plurality of resistors 525C, 525D (“R4”and “R5”). In some embodiments, the second divider 525C, 525D generatesa ratio of approximately 50% (e.g., “R4” and “R5” are both 10 kΩ); i.e.,it biases the signal about the midpoint (half) of the supply voltage,V_(cc) 526 (e.g., 2.5 V). It would be apparent to those skilled in theart to alter the first voltage divider 525A, 525B and the second voltagedivider 525C, 525D to achieve the necessary voltage scaling, such ascombining the two voltage dividers into a single voltage divider thatincludes a plurality of resistors.

The line input buffer 520 further includes a first voltage buffer 527coupled to the first galvanic isolator and voltage scaler subcircuit524, 525A, 525B, 525C, 525D, wherein the first voltage buffer 527 isconfigured to transmit a first output signal 529 (“LINE_IN_BUF”) to aprocessor 513. In some embodiments, the processor 513 is amicrocontroller unit (MCU) 513. In some embodiments, the first voltagebuffer 527 is an operational amplifier 527 (“OPAMP2”). Otherimplementations of the first voltage buffer 527 would be apparent tothose skilled in the art. In some embodiments, the first voltage buffer527 is coupled to the first voltage scaler 525A, 525B, 525C, 525D. Insome embodiments, the first voltage buffer 527 is coupled to the firstvoltage divider 525A, 525B. In some embodiments, the first voltagebuffer 527 is operational in the frequency range 200 Hz-4,000 Hz as wellas in power supply ranges up to 2.5 V. Although human hearing typicallydetects sounds ranging from 20 Hz to 20,000 Hz, the frequencies thatcorrespond to human speech are at the lower end of that range (around300 Hz to 3,400 Hz), so an operational frequency range of 200 Hz-4,000Hz is sufficient to transmit human voice intelligibly. Shutdownfunctionality with low supply current across up to four voltage buffers(e.g., four operational amplifiers) for high energy efficiency may alsobe desired. In some embodiments, the line input buffer 520 furtherincludes a voltage-limiting subcircuit 528 coupled to the first voltagebuffer 527, which limits an input to the first voltage buffer 527 towithin a predefined threshold if this input were to exceed the supplyvoltage V_(cc) 526 (e.g., 2.5 V). In some embodiments, the predefinedthreshold is the supply voltage V_(cc) 526 (e.g., 2.5 V). In someembodiments, the voltage-limiting subcircuit 528 is a Schottky barrierdiode 528 (“D2”). In other embodiments, the voltage-limiting subcircuit528 is a regulator, a divider, or another type of diode.

The line output driver 530 receives as input a second input signal 531(“DAC_OUT”) from the microcontroller unit (MCU) 513, which represents anaudio signal. The line output driver 530 includes a second voltagebuffer 532 configured to receive a second input signal from the MCU 513.In some embodiments, the second voltage buffer 532 is an operationalamplifier 532 (“OPAMP3”). Other implementations of the second voltagebuffer 532 would be apparent to those skilled in the art. The lineoutput driver 530 further includes a high-pass filter 533, 534 coupledto the second voltage buffer 532. In some embodiments, the high-passfilter 533, 534 is a DC block, filtering out frequencies below apre-determined threshold. In some embodiments, the high-pass filter 533,534 is implemented as a capacitor 533 (“C3”) operating in conjunctionwith a second transformer 534, where the capacitor 533 (“C3”) is a firstcomponent of the high-pass filter 533, 534, and the second transformer534 is a second components of the high-pass filter 533, 534. The lineoutput driver 530 further includes a second galvanic isolator andvoltage scaler subcircuit 534, 535A, 535B coupled to the high-passfilter 533, 534. In some embodiments, the audio line ground 509(“LINE_GND”) is coupled to the second galvanic isolator and voltagescaler subcircuit 534, 535A, 535B. In some embodiments, the high-passfilter 533, 534 and the second galvanic isolator and voltage scalersubcircuit 534, 535A, 535B share a component, a resistive element 534.In some embodiments, the resistive element 534 is a second transformer534 (“T2”), wherein the second transformer 534 includes a plurality ofwindings. In some such embodiments, the second transformer 534 (“T2”)performs both galvanic isolation and voltage scaling functions. In someembodiments, the audio line ground 509 (“LINE_GND”) is coupled to thesecond transformer 534 (“T2”). In other embodiments, the second galvanicisolator and voltage scaler subcircuit 534, 535A, 535B includes a secondtransformer 534 (“T2”) and a second voltage scaler 535A, 535B coupled tothe second transformer 534 (“T2”). In some embodiments, no amplificationnor attenuation from the second transformer 534 is needed, so the secondtransformer 534 is 1:1.

By modeling the primary winding of the transformer as a resistiveimpedance of 600Ω, the capacitor 533 (e.g., C3=10 μF) is being part of ahigh-pass filter with a cutoff frequency of approximately 26 Hz. Thecapacitor value may change so long as the cutoff frequency does notinterfere with the minimum target voice frequency that the transformeris sourced for, namely approximately 200 Hz, which corresponds to aminimum capacitance of approximately 1.3 μF. This filter design mayeasily be modified depending on the target frequencies or desired filterselection (e.g., using a high-pass filter that includes an operationalamplifier or an inductor). In some embodiments, the value of thecapacitor 533 is based on the impedance of the selected secondtransformer 534. In some embodiments, a capacitance of 10 μF for thecapacitor 533 and an impedance of 600Ω for the second transformer 534perform well with legacy intercom systems. To avoid applying a load tothe legacy intercom system output that is greater than what a standardapartment panel would apply, in some embodiments, the DC resistance ofeach winding of the plurality of windings of the second transformer 534is higher than the resistance of the legacy station speaker that it isreplacing. In some embodiments, the DC resistance of each winding of theplurality of windings of the second transformer 534 is 115Ω. In otherembodiments, the same effect is achieved by including a compensatingseries resistor so that the DC resistance of each winding of theplurality of windings of the second transformer 534 may be lower thanthe resistance of the legacy station speaker that it is replacing. Insome embodiments, the second transformer 534 is suitable for voiceaudio. For example, the TTC-5023 transformer supports a range of audiosignals of 200 Hz-4,000 Hz.

In some embodiments, the second voltage scaler 535A, 535B includes athird voltage divider 535A, 535B coupled to the second transformer 534(“T2”). In some embodiments, the third voltage divider 535A, 535Bincludes a plurality of resistors 535A, 535B (“R7” and “R10”). In someembodiments, the audio line ground 509 (“LINE_GND”) is coupled to atleast one of plurality of resistors 535A, 535B (“R7” and “R10”). In someembodiments, the third voltage divider 535A, 535B generates a ratio ofapproximately 4.5% (e.g., “R7” is 1 kΩ and “R10” is 47Ω), which closelyapproximates the signal range expected to be fed into an amplifier of alegacy intercom system. The determination of the 4.5% ratio took someexperimentation of various values to discover due to the very low inputthat is typically sent from legacy intercom stations to amplifiers inlegacy intercom systems, which results from using a speaker as a“reverse microphone” in most analog applications. Feeding in too high ofa value would likely damage the legacy system by overloading theamplifier. Exemplary tuning operations include: performing signal sweepsof signal to be fed into A/D converter to examine the attenuation ofaudio signals fed through the input transformer, performing signalsweeps to simulate D/A converter operations to examine the attenuationand degradation of audio sent through the output transformer, andexperimenting with various DC offsets to bias the input and outputsignals within the rail voltages of the voltage buffer (e.g. theoperational amplifier) as well as the A/D and D/A converters on the MCU513. For impedance matching, 50Ω is the appropriate speaker impedancerequired to avoid incurring audio interference back at the front doorspeaker.

In some embodiments, the line output driver 530 further includes asecond electrostatic discharge (ESD) and transient protection subcircuit536A, 536B coupled to the second galvanic isolator and voltage scalersubcircuit 534, 535A, 535B and configured to transmit a second outputsignal 537 (“LINE_OUT_BLD_REF”) to the wiring interface 511 for thelegacy intercom system. In some embodiments, the audio line ground 509(“LINE_GND”) is coupled to the second electrostatic discharge (ESD) andtransient protection subcircuit 536A, 536B. In some embodiments, thesecond electrostatic discharge (ESD) and transient protection subcircuit536A, 536B includes a second ESD resistor 536B (“R8”, e.g., 22Ω) and asecond transient-voltage-suppression (TVS) diode 536A (“D3”). In otherembodiments, the line output driver 530 does not includes a secondelectrostatic discharge (ESD) and transient protection subcircuit, inwhich case the second galvanic isolator and voltage scaler subcircuit534, 535A, 535B is configured to transmit a second output signal 537(“LINE_OUT_BLD_REF”) to the wiring interface 511 for the legacy intercomsystem

In some embodiment, the line input buffer 520 and the line output driver530 are partially or completely disabled upon normal operation of theintercom station until either “talk” or “listen” commands are initiatedcorrespondingly. Thus, power consumption is minimized.

FIG. 5C shows an exemplary circuit diagram 540 of the tone detectionsubsystem of the exemplary intercom station, in accordance with someembodiments of the invention. In some embodiments, as shown in thecircuit diagram, an audio line ground (“LINE_GND”) is a common line fromthe legacy intercom system, and a “GND” is an electrical ground. Thetone detection subsystem detects that a guest is activating the doorbell134 (and thus requesting to be buzzed in or to talk to the user) byinputting a tone in signal 541 (“TONE_IN”) and generating a tonedetection signal 549 (“TONE_DET”). The tone in signal 541 (“TONE_IN”) ispassed through the mount plate PCB without any connectivity to theisolation or relay subcircuits. It is first fed into an ESD/signalintegrity subcircuit 542A, 542B, which in some embodiments is comprisedof a resistor 542A (“R19”) and a TVS diode 542B (“D5”), similar to thosepresent in the line input buffer and line output driver. The signal thenis fed through additional protection sub-circuitry 543A, 543B, 543C,544A, 544B, which in some embodiments comprises a plurality of resistors543A, 543B, 543C (“R20”, “R21”, and “R22”) and a first diode 544A (“D4”)(e.g., BAT54 or a similar Zener diode), a second diode 544B (“D6”)(e.g., BZT52C3V3S-7 or a similar Schottky rectifier diode) before beingfed into an isolator 545 (“U2”). In some embodiments, the isolator 545(“U2”) is configured as an open collector device. Accordingly, pin 6 ofthe isolator 545 (“U2”) is connected directly to the 3.3 V voltagesource 546, pin 4 is fed directly to ground, and pin 5 (which is seen asthe output of the isolator 545) is connected into a small voltagedivider 547A, 547B, which in some embodiments comprises a top resistor547A (“R18”) and a bottom resistor 547B (“R23”), with the top resistor547A (“R18”) serving as a pullup resistor of the output line. In someembodiments, a small load capacitor 547C is placed on the output line toprovide signal stability.

In some embodiments, the isolator 545 (“U2”) operates as follows: If theinput signal is a logic “1”, the light-emitting diode (LED) in theisolator 545 (“U2”) may engage, which will cause a logic “1” to appearat the gate of the internal transistor. When this transistor isactivated, current from the 3.3 V voltage source has a path of lowestimpedance that passes through the transistor directly to ground, asopposed to flowing through the top 547A and bottom resistors 547B (“R18”& “R23”). This causes the output of the isolator 545 (“U2”), i.e., theinput of the Schmitt trigger 548 (“U3”), to be a logic “0”. As theSchmitt trigger 548 (“U3”) is non-inverting, the output of the Schmitttrigger 548 (“U3”), namely the tone detection signal 549 (“TONE_DET”),is a logic “0”. Alternatively, if a logic “0” is sent as an inputsignal, both sides of the internal LED will be at low voltage, and nocurrent is able to flow inside the isolator 545 (“U2”). This causes theinternal transistor to be turned off. When this occurs, the output (pin5) of the isolator 545 (“U2”) is automatically pulled up to 3.3 V asprovided by the voltage source, which corresponds to a logic “1”. Theoutput of the Schmitt trigger 548 (“U3”), namely the tone detectionsignal 549 (“TONE_DET”), is thus a logic “1”. In some embodiments, theSchmitt trigger 548 (“U3”) is implemented as an operational amplifier548. Experimental data demonstrating the operation of the tone detectionsubsystem is described with reference to FIG. 6C. Additional designconsiderations have been taken to improve power efficiency by removingthe need for inverting logic, and therefore removing the constantconnection from the 3.3 V voltage source 546 to the resistive load ofthe top 547A and bottom resistors 547B (“R18” & “R23”); however, theoverall functionality of the circuit remains the same. In someembodiments, the circuit also formats the input analog waveform into adigital format bound by ground and 3.3 V.

FIG. 5D shows an exemplary circuit diagram 550 of the universal relaysubsystem of the exemplary intercom station, in accordance with someembodiments of the invention. When used in combination with the audioisolation circuit shown in FIG. 5E, these circuits may implement thefunctional block diagram of the exemplary intercom station with separateuniversal relay and audio isolation subsystems as shown in FIG. 4C. Theuniversal relay subsystem includes a series of relays 554A, 554B, 554C,554D (“K1”, “K2”, “K3”, “K4”) connected to various signals from ananalog legacy intercom system. Relay A 554A (“K1”) allows connectivityto be made between the audio input-output 551B (“AUDIO_IO”) and audioline ground 559 (“LINE_GND”) signals of 3-wire systems. Note that insome embodiments and technical documentation, “LINE_GND” may be referredto as “AUDIO_COM”. It may also be configured to make a connectionbetween the doorbell 551A (“Door”) and audio line ground 559(“LINE_GND”) signals of 5- and 6-wire systems, depending on theconfiguration of the corresponding jumper 552A (“J1”). This connectionmay be used for door buzz operations. Alternatively, relay D 554D (“K4”)may be used to make a connection between the audio from station 551C(“AUDIO_FM_STATION”) and audio to station 551D (“AUDIO_TO_STATION”)signals, which performs the door buzz operation in 4-wire systems whenJumper 6 552D (“J6”) is connected.

Audio communication may be performed in a similar manner. As describedearlier with reference to FIGS. 5A and 5B, the universal relay and audioisolation subsystems in the wiring interface 511 for the legacy intercomprocesses the audio signal 551D (“AUDIO_TO_STATION”) and transmitsanother audio signal (“LINE_IN_BLD_REF”) 558B to a line input buffer 520of an audio input-output (I/O) circuit 512. Similarly, the wiringinterface 511 for the legacy intercom receives an audio signal 558A(“LINE_OUT_BLD_REF”) from a line output driver 530 of the audioinput-output (I/O) circuit 512. The audio signal 558B(“LINE_IN_BLD_REF”) is audio coming from the building via the audio tostation signal 551D (“AUDIO_TO_STATION”) (for 4-, 5-, and 6-wiresystems) or via the audio input-output signal 551B (“AUDIO_IO”) (for3-wire systems), depending on the configuration of Jumper 4 552C (“J4”),and may be sent to the main board by energizing relay C 554C (“K3”).Similarly, an audio signal 558A (“LINE_OUT_BLD_REF”) sent from the lineoutput driver 530 back to the building via the audio from station signal(“AUDIO_FM_STATION”) (for 4-, 5-, and 6-wire systems) or the audioinput-output signal 551B (“AUDIO_IO”) (for 3-wire systems), depending onthe configuration of Jumper 2 552B (“J2”), and may be sent from the mainboard back to the legacy station by energizing relay B 554B (“K2”).

Jumpers 3 555A (“J3”) and 5 555B (“J5”) may bypass passive components ifrequired in specific systems. In some embodiments, some or all jumpersare replaced by toggle switches or similar devices to increase usabilityby end users.

FIG. 5E shows an exemplary circuit diagram 560 of the audio isolationsubsystem of the exemplary intercom station, in accordance with someembodiments of the invention. When used in combination with theuniversal relay circuit shown in FIG. 5D, these circuits may implementthe functional block diagram of the exemplary intercom station withseparate universal relay and audio isolation subsystems as shown in FIG.4C. In some embodiments, Jumpers 9 562A (“J9”), 12 562B (“J12”), 13 562C(“J13”), and 14 562D (“J14”), are closed by default and are inserted forprototyping purposes only. Enable signals are sent to the isolators566A, 566B, 566C, 566D (“U1”, “U2”, “U3”, and “U4”). For each isolator566A, 566B, 566C, 566D, if the input signal is a logic “0”, thelight-emitting diode (LED) in the isolator may engage, which will causea logic “1” to appear at the gate of the internal transistor. As theoutput of an isolator 566A, 566B, 566C, 566D is pulled up to 3.3 Vprovided by a voltage source 563 (logic “1”) via the pullup resistors567A, 567B, 567C, 567D (“R10”, “R15”, “R18”, and “R21”), energizing thistransistor will allow current from that voltage source 563 to flow toground via the transistor and will result in a logic “0” on theRELAY_X_PW 568A, 568B, 568C, 568D (where “X” is “A”, “B”, “C”, or “D”)line corresponding to the input. Alternatively, if a logic “1” is sentas an input signal, both sides of the internal LED will be high voltage,and no current is able to flow inside the isolator 566A, 566B, 566C,566D. This causes the internal transistor to be turned off. When thisoccurs, the output (pin 5) of the isolator 566A, 566B, 566C, 566D isautomatically pulled up to 3.3 V as provided by the voltage source 563,which corresponds to a logic “1”.

FIG. 5F shows an exemplary circuit diagram 570 of the combined audioisolation and universal relay subsystems of the exemplary intercomstation, in accordance with some embodiments of the invention. Thiscircuit may implement the functional block diagram of the exemplaryintercom station with combined universal relay and audio isolationsubsystems as shown in FIG. 4D. This embodiment combines FIGS. 5D and 5Einto a single circuit. Components 574A (“K1”) and 574B (“K2”) eachcomprise two relays. Let the relays in component 574A (“K1”) be “RelayA” and “Relay B”, and the relays in component 574B (“K2”) be “Relay C”and “Relay D”, corresponding to their enable signals. Relay A (“K1”)allows connectivity to be made between audio input-output 571B(“AUDIO_IO”) and audio line ground 579 (“LINE_GND”) signals of 3-wiresystems. Note that in some embodiments and technical documentation,“LINE_GND” may be referred to as “AUDIO_COM”. It may also be configuredto make a connection between the doorbell 571A (“Door”) and audio lineground 579 (“LINE_GND”) signals of 5- and 6-wire systems, depending onthe configuration of the corresponding jumper 572A (“J1”). Thisconnection may be used for door buzz operations. Alternatively, relay D(“K4”) may be used to make a connection between the audio from station571C (“AUDIO_FM_STATION”) and audio to station 571D (“AUDIO_TO_STATION”)signals, which performs the door buzz operation in 4-wire systems whenJumper 6 572D (“J6”) is connected.

Audio communication may be performed in a similar manner. As describedearlier with reference to FIGS. 5A and 5B, the universal relay and audioisolation subsystems in the wiring interface 511 for the legacy intercomprocesses the audio signal 571D (“AUDIO_TO_STATION”) and transmitsanother audio signal 578B (“LINE_IN_BLD_REF”) to a line input buffer 520of an audio input-output (I/O) circuit 512. Similarly, the wiringinterface 511 for the legacy intercom receives an audio signal 578A(“LINE_OUT_BLD_REF”) from a line output driver 530 of the audioinput-output (I/O) circuit 512. The audio signal 578B(“LINE_IN_BLD_REF”) is audio coming from the building via the audio tostation signal 571D (“AUDIO_TO_STATION”) (for 4-, 5-, and 6-wiresystems) or via the audio input-output signal 571B (“AUDIO_IO”) (for3-wire systems), depending on the configuration of Jumper 4 572C (“J4”),and may be sent to the main board by energizing relay C (part of “K2”).Similarly, an audio signal 578A (“LINE_OUT_BLD_REF”) sent from the lineoutput driver 530 back to the building via the audio from station signal571C (“AUDIO_FM_STATION”) (for 4-, 5-, and 6-wire systems) or the audioinput-output signal 571B (“AUDIO_IO”) (for 3-wire systems), depending onthe configuration of Jumper 3 572B (“J3”), and may be sent from the mainboard back to the legacy station by energizing relay B (part of “K1”).

Jumpers 2 575A (“J2”) and 5 575B (“J5”) may bypass passive components ifrequired in specific systems. In some embodiments, some or all jumpersare replaced by toggle switches or similar devices to increase usabilityby end users.

FIGS. 6A, 6B, 6C, and 6D show various exemplary electrical waveformsassociated with an exemplary legacy intercom system and an exemplaryintercom station, in accordance with some embodiments of the invention.Most attempted isolation methods could not successfully extract ringsignals (or listen signals) due to low amplitude thresholds. To solvethis problem, simultaneously selecting a specific isolation method aswell as tuning the passive network leads to the isolator systemdisclosed herein. With reference to the tone detection system shown inFIG. 5C, the resistances R19, R20, and R21 are increased up to around200Ω to limit the potential of damage to the isolator. Various diodecombinations were attempted to both prevent damage as well as limitnoise on the signal line. Note that the “LINE_GND” line shown in thevarious figures is not an electrical ground but rather is a common audioline from the legacy intercom system. Incorrect installation ordifferent specifications of legacy systems may cause unforeseenbehaviors that the universal intercom station must protect against.Furthermore, note that in some embodiments and technical documentation,“LINE_GND” may be referred to as “AUDIO_COM”.

FIG. 6A shows exemplary electrical waveforms 610 of a door buzz signalfrom the intercom station of an exemplary legacy intercom system, inaccordance with some embodiments of the invention. With reference to theanalog legacy wiring interface, audio isolation, and universal relaysubsystems discussed above regarding FIGS. 5A, 5B, 5C, 5D, 5E, and 5F,the solid waveform 611 represents the signal detected on theAUDIO_TO_STATION line and the waveform 612 represents the signaldetected on the AUDIO_FROM_STATION line when a door buzz operation isperformed on a 4-wire analog PK543 intercom station, which entailsshorting the two aforementioned lines. It would be apparent to thoseskilled in the art to replicate the necessary door buzz signal based onthe experiments performed on legacy intercom stations such as the 4-wireanalog PK543 intercom station. Note that digital systems, in contrast,generally do not send door buzz signals by merely shorting two wires,but instead send instructions to an intercom central unit (ICU). In someembodiments, the wires are shorted for at least a minimum period of timeregardless of how long the “door” button is pressed by a user.

In an example configuration of the PK543, pressing the “door” button ona 4-wire analog PK543 intercom station applies a closure across theintercom station's terminals 2 and 3. The closure is routed to the PK543amplifier's terminals 2 and 3. After the amplifier senses the closure,it provides 16 V of AC voltage across the amplifier's terminals D and K.Meanwhile, DC voltage is also present across terminals L+ and L− as theunfiltered output of a full-wave rectifier fed by the same 16 V of ACvoltage, which is applied to the door release mechanism to unlock thedoor. In one variation, a closure the across the PK543 amplifier'sterminals 1 and E can be used to output 16 V of AC voltage across theamplifier's terminals D and K.

FIG. 6B shows an exemplary electrical waveform 620 of a door ring signalfrom the lobby panel of an exemplary legacy intercom system, inaccordance with some embodiments of the invention.

FIG. 6C shows exemplary electrical waveforms of a door ring signal fromthe lobby panel of an exemplary legacy intercom system and the responsefrom the tone detection subsystem of an exemplary intercom station, inaccordance with some embodiments of the invention. With reference to thetone detection circuit described above regarding FIG. 5C, the solidwaveform 631 represents the tone detection signal (“TONE_DET”) and thewaveform 632 represents the tone in signal (“TONE_IN”). These waveformsconfirm that the tone detection circuit described above regarding FIG.5C operates as intended, by inverting, scaling, and limiting the tone insignal appropriately.

FIG. 6D shows an exemplary electrical waveform 640 of a user yellinginto the microphone of the lobby panel of an exemplary legacy intercomsystem, in accordance with some embodiments of the invention.

Audio System

FIG. 7A shows a schematic of various components of an exemplary intercomsystem, including components of an exemplary intercom station, when aguest speaks 704 to a user 720, in accordance with some embodiments ofthe invention. In some embodiments, the audio signal 702 from theintercom lobby 706 (e.g., a guest's audio message) goes through anisolation component or buffer circuit on a printed circuit board (PCB)(not shown) in the intercom station. The output 708 from the isolationcomponent or buffer circuit 704 is then inputted into an ADC 710 on theprocessor (e.g., the microcontroller), which digitizes the audio signal708 and organizes it into digital packets sent to an audio digester 712,which transforms the information into a format that may be received bydownstream stages. Depending on whether the end goal is the speaker onthe user's mobile device 718 or the speaker 724 on the intercom station,the audio digester 712 routes the packets 722 accordingly. If theformer, the digital packets 722 are then sent to the backendcloud-computer service (e.g., AWS) 716, which forwards the digitalpackets to the mobile app 718. The mobile app 718 then uses asoftware-based digital-to-analog converter (DAC) 714 to recover theoriginal audio signal from the digital packet representation. Thisrecovered audio signal is then outputted to the user 720 via the mobiledevice's speaker. In some embodiments, the steps in this chain areregulated by a standard network protocol, such as Message QueuingTelemetry Transport (MQTT), which runs over TCP/IP, or WebRTC. In someembodiments, the network protocol includes security and privacy features(e.g., authentication or encryption of signals sent and received).

In some embodiments, the ADC and/or the DAC are external from the MCU,e.g., an external digital signal processing (DSP) chip located elsewhereon the PCB. In some embodiments, the ADC/DAC is implemented in hardwareonly (e.g., ASIC). In other embodiments, the ADC/DAC is implemented insoftware only (e.g., sampling algorithm).

In some embodiments, optocoupler technology is employed to implement theisolation circuitry. In other embodiments, especially to avoid thepotential for the LEDs in opto-components to wear out over time,capacitive barriers, transformers, radiofrequency (RF) isolators, ortransistor-transistor logic (TTL), are used.

FIG. 7B shows a schematic of various components of an exemplary intercomsystem, including components of an exemplary intercom station, when auser speaks 726 to a guest 704, in accordance with some embodiments ofthe invention.

In some embodiments, the backend cloud computing service 716 storesrecordings of audio from the microphone of the lobby, the microphone ofthe intercom station, and the microphone of the mobile device. A user720 is able to later access and playback these recordings via the mobileapp 718 or website, which may be useful in cases where the user missedan audio transmission or would later like a further record of who was inthe building. In some embodiments, the user 720 may download the audiorecordings. A user 720 may also record an audio conversation between theuser 720 and a guest 704. In some embodiments, the user 720 may elect toactivate or deactivate the recording feature or may set in advanceconditions under which the recording feature is activated. In someembodiments, the audio is encrypted from end to end.

In some embodiments, the backend cloud-computing service 716 may send apre-recorded voice message to the lobby speaker 706 upon receiving adoorbell ring, prompting the guest to wait 704 or to leave a voicemailthat will be recorded. In some embodiments, the host 720 may generatemultiple pre-recorded voice messages and create rules that determinewhich voice message is played. In other embodiments, if the backendcloud-computing service 716 determines that the user 720 is likely to beabsent from the apartment unit and is also not responding to the mobileapp notifications, the backend cloud-computer service 716 will send apre-recorded voice message (e.g., “the host is unavailable”) to thelobby speaker 706 upon receiving a doorbell ring. Use cases may includean away message while the user is on vacation.

Message Journeys

FIGS. 8A, 8B, 8C, 8D, 8E, and 8F show exemplary message journeys forvarious use cases of the exemplary intercom station, in accordance withsome embodiments of the invention.

In FIG. 8A, a guest 802 presses a doorbell 804 to request the door beingunlocked. In response, the lobby panel 806 (building intercom) sends therequest 808 (e.g., via a warble tone) to the intercom station 810 (BuzrPro). The intercom station then sends the request (along with the deviceID corresponding to the intercom station) to the backend cloud-computerservice 814 (AWS: IoT Core) via a standard network protocol, such asMessage Queuing Telemetry Transport (MQTT). In some embodiments, thenetwork protocol includes security and privacy features (e.g.,authentication or encryption of signals sent and received). The backendcloud-computer service finally forwards the request to a user 818 via amobile app notification 816.

In FIG. 8B, a user 836 pushes the virtual talk button 834 on a mobileapp and speaks into the microphone of user's mobile device. The talkrequest and the audio signal are sent to the backend cloud-computerservice 832 (AWS: IoT Core), which forwards the talk request (along withthe device ID) and the audio signal to the intercom station 828 (BuzrPro) via a standard network protocol 830 (MQTT). The intercom stationthen sends the audio signal 826 to the lobby panel 824 (buildingintercom), which then generates an audio sound 822 via a speaker for aguest 820 at the lobby to hear.

In FIG. 8C, a user 850 pushes the virtual listen button 848 on a mobileapp. The listen request is sent to the backend cloud-computer service846 (AWS: IoT Core), which forwards the listen request (along with thedevice ID) to the intercom station 842 (Buzr Pro) via a standard networkprotocol 844 (MQTT). The intercom station then sends listen request tothe lobby panel 840 (building intercom), which then activates themicrophone in the lobby panel to begin sensing sound from the lobby. Theguest 838 is then able to speak to the user 850.

In FIG. 8D, a guest 852 speaks 854 into a speaker of a lobby panel(building intercom) 856, which has been activated in accordance withFIG. 8C. The audio signal 858 generated by the guest speaking (alongwith a reference to the intercom station ID) is forwarded to theintercom station 860 (Buzr Pro). The intercom station then sends theaudio signal (along with the device ID corresponding to the intercomstation) to the backend cloud-computer service 864 (AWS: IoT Core) via astandard network protocol 862 (MQTT). The backend cloud-computer service864 finally forwards the audio signal to the user 868 via the mobile appas long as the user 868 continues to hold the virtual listen button 866of the mobile app.

In FIG. 8E, the user 877 releases the virtual listen button 876 of themobile app, which has been activated in accordance with FIG. 8C. The“stop listen” request is sent to the backend cloud-computer service 875(AWS: IoT Core), which forwards the “stop listen” request (along withthe device ID) to the intercom station 873 (Buzr Pro) via a standardnetwork protocol 874 (MQTT). The intercom station then halts thereception of audio signals from the lobby panel 872 (building intercom).After this time, if the guest 870 continues to speak 871 into themicrophone in the lobby panel, the audio signal from the guest 870 doesnot reach the intercom station, and hence does not reach the user 877.

In FIG. 8F, a user 886 pushes the virtual door (“buzz”) button 885 onthe mobile app to unlock the door. The unlock request is sent to thebackend cloud-computer service 884 (AWS: IoT Core), which forwards theunlock request (along with the device ID) to the intercom station 882(Buzr Pro) via a standard network protocol 883 (MQTT). The intercomstation then sends the unlock request 881 to the lobby panel 880(building intercom), which unlocks the door for the guest 878 to enterthe building 879.

FIG. 8G shows a schematic of various components of an exemplary intercomsystem when a guest sends an unlock request 890, in accordance with someembodiments of the invention. The message journeys for these use casesare shown and described above in FIGS. 8A and 8F. In some embodiments,the intercom station is by default in a low-power (“sleep”) mode. Whenthe intercom station receives an unlock request, it then “awakened” andenters a high-power mode.

FIG. 8H shows a schematic of various components of an exemplary intercomsystem when a user and a guest speak to each other 895, in accordancewith some embodiments of the invention. The message journeys for theseuse cases are shown and described above in FIGS. 8B, 8C, 8D, and 8E.

Accounts and Registering an Intercom Station to an Account

A person may create an account with a password on the mobile app orthrough a website associated with the intercom station (“intercomstation website”). The account may also be created via a third-party login system, such as Google, Facebook, or Apple, so that the backendsystem may associate a particular user with a particular intercomstation. When the mobile app is first downloaded onto a mobile device,the user is prompted to either sign in with an account that is alreadymade or by setting up a new account. In some embodiments, the mobile apprequires the user to input a mobile number with two-factorauthentication. In some embodiments, the mobile app requiresverification via e-mail, text, or other messaging means. In someembodiments, the verification is a form of two-factor authentication. Insome embodiments, the mobile app requires confirmation that the user isauthorized before being able to control the intercom station. This mayinclude providing lease information to validate that the user lives inor owns the unit he/she is intending to install the intercom station.The user's account may be suspended upon the expiration of the leaseover the apartment until unless a lease renewal is confirmed. In someembodiments, the user provides a photo of the legacy device that he/shewould like to replace in the apartment to ensure compatibility andreduce time on the phone with customer service. This function may beperformed by, for example, using machine vision and image recognition toidentify legacy devices from a user-uploaded photograph.

The user may be prompted in the mobile app to register a new intercomstation to the user's account. In the “set up your device” mode, theuser registers the new intercom station by scanning a QR code or otheridentifying code on the intercom station or manually entering anintercom station ID number to associate the user's account with thisparticular intercom station. The user may also dissociate the intercomstation from their account.

Once an intercom station is associated with a user, it may be configuredto connect to the local Wi-Fi network in the user's apartment unit. Themobile app instructs the user to push the Wi-Fi pairing button on theintercom station, which prompts the intercom station to emit its ownWi-Fi network to connect to the user's mobile device. The mobile appthen requests that the user enter the credentials for accessing thelocal Wi-Fi network. When the intercom station successfully connects tothe local Wi-Fi network, it provides a “connection successful” messageto the user if it connects to the network intended by the user. Furtherassociations also begin on the backend cloud-computing service. Forexample, in some embodiments, a “Just in Time Registration” (JiTR)process begins, the intercom station requests the creation of a CAcertificate, and the certificate is registered with the backendcloud-computing service. In some embodiments, the intercom stationclears previously stored Wi-Fi credentials upon the press of a button orother input.

Mobile Application Fundamentals

In some embodiments, the intercom system includes features such as theuse of a guest mobile app, virtual keys for guests to enable theunlocking of the door when the user is not present, geofencing, theautomatic unlocking of the door upon request, and the unlocking of thedoor via the intercom station or the mobile app without an unlockrequest sent by a guest.

In some embodiments, the mobile app associated with the intercom stationhas two modes: host (user) and guest. The host mode is for a user whohas access to the apartment unit in which the intercom station isinstalled; the host mode enables the host to perform all the of theintercom station functions remotely, as well as other functionsdescribed in this disclosure. The guest mode is for a guest who seeksaccess to the building. In some embodiments, there is a stand-alone appfor integration partners.

An account may be designated as a host, as a guest, or as both a hostand a guest (for different intercom stations). An account may bedesignated as a host for multiple intercom stations (e.g., a real estateagent managing multiple apartment units), and/or as a guest for multipleother intercom stations (e.g., a cleaning service with multipleclients). A single particular intercom station may be associated withmultiple hosts (e.g., members of the same household living the apartmentunit) as well as with multiple guests. In some embodiments, the mobileapp permits a single mobile device to save multiple account and passwordcombinations.

In some embodiments, the mobile app enables multiple users tocommunicate with one another. This may be, for example, via textmessaging, via requests for a virtual key, or via request for amodification to an existing virtual key (e.g., delay the expirationtime). When a guest requests a virtual key, the host receives anotification on his/her mobile device, after which the host may grant,deny, or ignore the request via the mobile app. In some embodiments, themobile app is integrated with third-party mobile messaging apps, such ase-mail, SMS, WhatsApp, iMessage, Facebook Messenger, or Google Voice.

Unlock the Door via Mobile Application

In some embodiments, the intercom station enables a user to perform thedoor, talk, and listen functions remotely through the mobile app as ahost. The mobile app includes a graphical user interface (GUI) thatreproduces the physical interface of the intercom station, such avirtual talk button that enables the user to speak to the guest, avirtual listen button that enables the user to listen to sounds in thelobby including the guest's voice, and a virtual door button thatenables the user to approve the request to unlock the door. In someembodiments, the mobile device enables these functions by means otherthan virtual buttons, such as voice commands.

FIG. 9A shows an exemplary home screen of a graphical user interface(GUI) 900 of an intercom station mobile app, in accordance with someembodiments of the invention. The top row menu has three items: “keys”902, “your Buzr” 904, and “account” 906. The user is in the home screen908 when “your Buzr” 904 is selected. The home screen 908 shows thethree virtual buttons described above: talk 912, listen 914, and door(“buzz in”) 910.

When a guest outside the door requests unlocking the door, he or sheactivates (“rings”) a doorbell on the lobby panel that corresponds tothe guest's target apartment unit. When the doorbell is activated, thelobby panel sends the unlocking request as a signal to the ICU, whichrelays it to the intercom station in the target apartment unit. Theintercom station then relays the unlocking request to the backendcloud-computing service, which in turn relays the unlocking request tothe mobile app. In response, the mobile app generates a notification(“doorbell ring notification”) to the user that the request has beenmade. Such a notification may include an audible sound being emittedfrom the mobile device, a series of vibrations of the mobile device, orother push notifications typical for mobile devices.

Upon receiving the notification, the user may approve of the unlockingrequest by activating the virtual door button on the GUI, which causesthe mobile app to send the unlocking approval to the backendcloud-computing service, which in turn relays the unlocking approval tothe intercom station. This action may be performed by touch-sliding thedoor (“buzz in”) button from a left-most position 910 in FIG. 9A to theright 912, which transitions the GUI to that shown in FIG. 9B, whichshows an exemplary “buzzing” screen 917 of a GUI of an intercom stationmobile app and the door button in a right-most position 915, inaccordance with some embodiments of the invention. In some embodiments,the user may select the buzz length for each door open request. Apotential use case for a longer buzz length is in multi-door buildings.For example, consider a building where a guest first encounters a firstdoor that leads to an enclosed area, where the guest then encounters asecond door before entering the building proper. The guest must bebuzzed through both doors in order to enter the building. In suchmulti-door buildings, where the lobby panel is outside the first door,the user must buzz the guest for a period of time long enough or asufficient number of times for the guest to open the first door, walkthrough the enclosed area, and finally open the second door. Thus, insome embodiments, the intercom station's buzz signal is longer than apre-determined threshold (namely, the typical minimum amount of time itwould take a guest to open a door and walk through the enclosed area).In other embodiments, the user may alter the intercom station's buzzsignal length. In still other embodiments, the user may instruct theintercom station to send multiple buzz signals.

The intercom station then relays the unlocking approval as a signal tothe ICU, which sends a request to the door lock to unlock the door,“buzzing” the guest in. In some embodiments, the mobile app supports theunlocking of the door without a prior unlock request sent by a guest.This is achieved by the host activating the virtual unlock button or itsequivalent via the mobile app.

When a user wishes to halt the unlocking of the door, he/she may thenrelease the door (“buzz in”) button, which transitions the GUI to thatshown in FIG. 9C, which shows an exemplary “buzzed” screen 916 of a GUIof an intercom station mobile app, in accordance with some embodimentsof the invention. On this screen, the GUI shows confirmation that thebuzz signal has been sent 916. After a brief pause, the GUI transitionsback to the home screen shown in FIG. 9A.

Some legacy intercom systems include a “talk interlock” feature builtinto either the base controller (for digital systems) or the amplifier(for analog systems) component, as referenced in FIG. 1A. This featurerequires that the user activate the “talk” feature (e.g., by pressing a“talk” button) before he or she is able to buzz the door open. Onemotivation for this feature is that it forces the user to identity theguest at the lobby requesting entry before unlocking the door withoutany knowledge of the guest's identity. To interface with such a featurein legacy intercom systems, some embodiments of the intercom stationensure that the talk interlock requirement is met before sending anunlock request (e.g., a guest applies a virtual key without a user tofirst speak to the guest). In some embodiments, the intercom stationpulses the talk line. For example, in analog systems, the enable of aMOS relay is set “high” for a sufficiently long period of time (e.g.,approximately 1 second) before sending any buzz signals to ensure thatthis talk interlock requirement is met and the intercom station is ableto buzz successfully.

In some embodiments, the intercom station includes a “device mute”feature, where a user may mute the intercom station temporarily. Typicaluse cases include avoiding awakening occupants already asleep, avoidinginterrupting activity in the building unit, and generally establishing aquiet environment. In such embodiments, the intercom station isconfigured to intercept and mute all audio signals that would otherwisebe sent to the intercom station (e.g., doorbell rings). In someembodiments, all communication with the building door may still beaccomplished via the mobile application while the intercom station ismuted. In some embodiments, rather than muting all audio signals, theuser may determine how much signals are altered. For example, the usermay adjust the volume of a doorbell ring or of audio communication, ormay select from a variety of ringtones, which may be pre-recorded audioor PWM waveforms. Such embodiments may be implemented by intercepting anincoming signal at the processor (e.g., the microcontroller unit) withthe audio buffer circuitry disclosed with reference to FIGS. 5B and 5C,and responding with the proper action upon receiving that incomingsignal.

Verbal Communication Via Mobile Application

In some embodiments, the intercom system enables the user via the mobileapp and the guest to speak to each other. When the mobile app notifiesthe user that an unlock request has been sent, the user has the optionof activating the microphone of the mobile device and the speaker of thelobby panel, but not the speaker of the mobile device nor the microphoneof the lobby panel, by pressing and holding down the virtual talk button912 on the GUI shown in FIG. 9A. Once these devices are activated, theGUI transitions to that shown in FIG. 9D, which shows an exemplary“talking” screen 920 of a GUI of an intercom station mobile app, inaccordance with some embodiments of the invention. Now, the user mayspeak to the guest at the lobby. When the user releases the virtual talkbutton (the white circle 918 in FIG. 9D), the microphone of the mobiledevice and the speaker of the lobby panel are deactivated, and the usermay no longer speak to the guest. The GUI then transitions back to thatshown in FIG. 9A.

In some embodiments, the intercom system enables the user via the mobileto passively listen to sounds in the lobby, including the guest's voice,by pressing and holding down the virtual listen button 914 on the GUIshown in FIG. 9A, which activates the microphone of the lobby panel andthe speaker of the mobile device, but not the speaker of the lobby panelnor the microphone of the mobile device. Once these devices areactivated, GUI transitions to that shown in FIG. 9E, which shows anexemplary “listening” screen 930 of a GUI of an intercom station mobileapp, in accordance with some embodiments of the invention. Now, theguest in the lobby may speak to the user. When the user releases thevirtual listen button (the white circle 922 in FIG. 9E), the microphoneof the lobby panel and the speaker of the mobile device are deactivated,and guest user may no longer speak to the user. The GUI then transitionsback to that shown in FIG. 9A. By alternately pressing the virtual talk912 and the virtual listen buttons 914 on the GUI 900, the user mayconduct a conversation via mobile device with a guest at the lobby.

In some embodiments, if the user receives an incoming telephone callwhile conversing with a guest via the mobile app, the telephone call isdisplayed in a heads-up notification as to not remove focus from themobile app. The user has the options of answering the call (whichdisconnects the conversation with the guest) or ignoring the call (whichcontinues the conversation with the guest uninterrupted).

In some embodiments, whenever the virtual talk 912 or virtual listenbuttons 914 are pressed, held, or released, a signal encapsulating therequest is sent from the mobile device to the backend cloud-computingservice, which in turn relays the request to the intercom station. Theintercom station then relays the request as a signal to the ICU, whichsends the request to the lobby panel to activate or deactivate theappropriate devices. Whenever audio signal is transmitted (e.g., theuser holds down the virtual talk button while speaking into the mobiledevice microphone, the user holds down the virtual listen button 914while the guest is speaking into the lobby panel microphone), the signalis routed between mobile device, the backend cloud-computing service,the intercom station, the ICU, and the lobby panel.

In some embodiments, the microphone and the speaker of the intercomstation are inactivated when the microphone and the speaker of themobile device are activated as discussed above regarding the operationof the virtual talk and the virtual listen functions. In someembodiments, if multiple users who are hosts of the same intercomstation (e.g., two roommates) attempt to speak to a guest at the lobbyby using the virtual talk function on their respective mobile apps, thenonly the first one to activate the virtual talk function will be able totalk, and the speaker of the lobby panel will emit the sounds from themicrophone of the mobile device of that first user. The second userreceived a notification on their mobile device indicating that someoneelse is speaking to the lobby.

Automatic Unlocking

In some embodiments, the mobile app supports the automatic unlocking ofthe door upon request by a guest. This is achieved by the hostactivating the automatic unlocking feature via the mobile app orintercom station website. The activation is stored in the backendcloud-computing service. After this feature has been activated, whenevera guest requests the door to be unlocked by ringing the doorbell on thelobby panel, the intercom station will automatically grant the requestby confirming with the backend cloud-computing service that theautomatic unlocking feature is activated. The host may deactivate theautomatic unlocking feature any time. In some embodiments, the host mayset in advance conditions under which the automatic unlocking feature isactivated. For example, the feature may be activated over a set timeperiod (“between 5 pm and 7 pm tomorrow”) or may be activated for afixed number of unlock requests (“expires after 5 unlock requests”). Insome embodiments, the user will receive a notification on the mobile appwhenever the automatic unlocking feature is used by a guest or by anintegration partner. In some embodiments, each automatic unlockingrequest is recorded.

Virtual Keys

In some embodiments, the mobile app supports the creation (“activation”)of virtual keys for guests to enable the unlocking of the door withoutthe contemporaneous participation by the host user, which is useful whenthe host is not physically present in the apartment unit and also maynot be able to access the mobile app immediately. When the useractivates a virtual key, the mobile app sends a virtual key activationsignal to the backend cloud-computing service (CCS). The virtual keysare stored in the backend CCS. FIG. 10A shows an exemplary “keys” screen1000 of a GUI of an intercom station mobile app, in accordance with someembodiments of the invention. In this example, the list of activevirtual keys 1002 is shown. The guest may be identified by, for example,full name, nickname, username, e-mail address, phone number, or otheridentifying information. The guest may or may not have the mobile appnor corresponding account installed on his or her mobile device. If theguest has the mobile app and corresponding account installed on his orher mobile device, the guest is able to use a virtual unlock button onthe app to apply the virtual key, which unlocks the door. In someembodiments, whether the guest has the mobile app and correspondingaccount installed on his or her mobile device or not, the guest receivesa URL link via text message or e-mail. When the guest clicks the URLlink, the virtual key is applied, which unlocks the door. Whenever aguest applies a virtual key by any means, the backend cloud-computingservice (CCS) sends a signal to the intercom station to request theintercom station to send a request to the ICU to unlock the door.

Using the mobile app or intercom station website, a host creates avirtual key for a particular guest. FIG. 10B shows an exemplary “issuenew key” screen 1010 of a GUI of an intercom station mobile app, inaccordance with some embodiments of the invention. The virtual key mayhave a name, an ID number, or a code 1004 (“Mom & Dad” in this example).In some embodiments, the host may set in advance conditions under whichthe virtual key is active, which enhances the security of an otherwiseunsupervised system. For example, the feature may exist only over a settime period 1006, 1008 (“between 5 pm and 7 pm tomorrow”, “between noonand 1 pm every Tuesday”) or may work only for a fixed number of unlockrequests (“expires after 5 unlock requests”). In the example, shown inFIG. 10B, the start date/time 1006 is Nov. 25, 2020 at 1:00 pm, the enddate/time 1008 is Dec. 19, 2020 at 6:00 pm, and the virtual key repeatsdaily 1012. These limited virtual keys may be useful for variouscategories of guests. For example, for a host renting out the apartmentunit as a short-term rental (e.g., via Airbnb) may create virtual keysfor their guests corresponding only to the time periods of theirreservations so that the guests may not access the building outside oftheir reservation period. A host who expects a dog-walker or cleaningservice at particular times during the day or other schedule may createa virtual key so that those guests may not access the building outsideof those expected times.

FIG. 10C shows an exemplary “share key” screen 1020 of a GUI of anintercom station mobile app, in accordance with some embodiments of theinvention. Once the user is ready to share the key with the intendedguest, he/she reviews the key information and enters the intendedrecipient's contact information, such as a telephone number 1014 ore-mail address 1016. In some embodiments, the mobile app accesses thecontact list available in the user's mobile device to index the possibleentries for the recipient's contact information. The user then clicks on“share key” 1018 to send the key to the intended recipient.

The host user may deactivate a virtual key at any time. FIG. 10D showsan exemplary “deactivate” screen 1030 of a GUI of an intercom stationmobile app, in accordance with some embodiments of the invention. When auser wishes to deactivate a virtual key, he/she clicks on the“deactivate” button 1022. The user is then asked to confirm thedeactivation.

In some embodiments, if a guest finds that the given virtual key doesnot work when applied, he/she may use support features in the app torequest a new virtual key from the user. The user would then receive anotification for the request, and may respond by resending the virtualkey, generating a new active virtual key, or ignoring the request.

In some embodiments, the user receives a notification on the mobile appwhenever a virtual key is activated, deactivated, or applied. In someembodiments, each application of a virtual key is recorded. Thisinformation may include the ID of the virtual key, the identity of theguest applying the virtual key, and the date/time of the application. Insome embodiments, the backend cloud-computing service (CCS), localserver, local device, or mobile application generates a record ofinstances where an integration partner used a virtual key.

Geofencing

In some the embodiments, the virtual key may be applied via geofencing.The host may set via the mobile app or intercom station website a“geofence”, or a set of lines or curves. The virtual key is appliedwhenever the guest's mobile device is determined to breach the geofence.In some embodiments, the geofence is a closed curve encompassing ageographical region. In other embodiments, the geofence is an opencurve. For example, the host may set the geofence to be a circle with a10-meter radius centered around the building's lobby door. This way, thedoor will automatically unlock when the guest is about to arrive at thedoor. In some embodiments, the mobile app may access the host mobiledevice's mapping functions (e.g., Google Maps) to enable the host toview and choose a geofence. In some embodiments, the mobile app mayaccess the guest's mobile device's location functions (e.g., GPS,cellular network triangulation) to determine the guest's location. Insome embodiments the geofence is used as a prerequisite for applying avirtual key.

Other Automatic Keys

Other types of automatic keys may be implemented. In some embodiments,the host may provide a guest with a service phone number to call, uponwhich entering a unique PIN would automatically unlock the door. In someembodiments, the guest may talk to a call center for assistance. In someembodiments, the guest may speak into the lobby microphone andsuccessfully unlock the door by saying the correct password set by thehost. In these embodiments, speech recognition technology determineswhat the guest is saying. In some embodiments, the speech recognition isperformed at the intercom station. In other embodiments, the speechrecognition is performed in the cloud-computing service.

Third-Party Integration

In some embodiments, the intercom station supports integrations withvarious types of third-party services, including delivery providers,service providers, and short-term rental services (Airbnb). For example,suppose the intercom station is integrated with a food delivery service.When the user places an order from the food delivery service's mobileapp or website, the intercom station automatically generates a virtualkey or other automatic key (e.g., PIN, password) as described earlier inthis disclosure. The delivery person would then be provided with thevirtual key or other automatic key (“key”) for automatic entry into theuser's building. The key may be provided to the delivery person inseveral ways: via the delivery person's intercom system mobile app as aguest, via the food delivery service's app, via text message, or viae-mail. In some embodiments, the virtual key or other automatic key isvalid only within a reasonable time frame for food delivery (e.g.,within 30 minutes of the expected delivery time), which the user mayset. In another example, suppose the intercom station is integrated witha short-term rental service, such as Airbnb. When a guest books theuser's apartment unit from the short-term rental service's mobile app orwebsite, the intercom station automatically generates a virtual key orother automatic key (e.g., PIN, password). The guest would then beprovided with the virtual key or other automatic key (“key”) forautomatic entry into the user's building. In addition to the key beinginvalid outside of the reservation time as described earlier in thisdisclosure, the key may expire in a manner tied to activity via theshort-term rental service, e.g., automatic key expiration upon the guestchecking out of the short-term rental via that service's app.

In some embodiments, the intercom station may be integrated with anexternal video camera system near the lobby panel or elsewhere in thebuilding. In some embodiments, the intercom station may be integratedwith building management platforms, brokerage services, and/or leasingservices.

Monitoring

In some embodiments, the intercom station monitors various features. Forexample, it monitors its own battery levels and communicates to the userif and when the battery levels are below a pre-determined threshold(e.g., energy remaining in the batteries is only 10% of the totalcapacity of the batteries). The user may view this information in a“device health” screen in the mobile app. The mobile app sends pushnotifications to the user when the battery has gone below a threshold(e.g., 25%) so that the user may proactively change or plan a change inthe batteries. In some embodiments, low power mode is a default unlessthe intercom station is actively used, not merely when the batteries arelow on remaining energy. In some embodiments, this is achieved inWGM160P via integrated “DTIM” modes.

The intercom station may monitor its Wi-Fi connectivity and communicateto the user if the connectivity is poor. Similarly in the “devicehealth” screen in the mobile app, the user may view the strength of theWi-Fi connection. The backend cloud-computing service (CCS), such asAmazon Web Services (AWS), sends push notifications to the user when theintercom station has gone off-line.

The mobile app may monitor usage by maintaining records of who openedthe door and when, allowing the user to see exactly when someone was intheir building as a result of their intercom station, via a screen inthe mobile app. FIG. 10E shows an exemplary “activity history” screen1040 of a GUI of an intercom station mobile app, in accordance with someembodiments of the invention. One use case for this feature is forthird-party verification. For example, suppose a delivery servicereceives a unique virtual key (perhaps via third-party integration asdescribed above) to leave a package in the user's building. If thedelivery service later claims that their delivery person had alreadydelivered the package, the user would be able to verify whether thatunique virtual key was activated as claimed. In some embodiments, thedelivery service or delivery person would receive a confirmation notice(via, e.g., text message or e-mail) that the virtual key wassuccessfully activated. This feature also provides security to the userand to the building by knowing who was in the building and when.

In some embodiments, the intercom station provides the user with livingquality information through on-device passive sensors that permit theuser to see, for instance, whether the temperature of the apartment unitis within a certain range (e.g. legal range based on street address),whether there is a gas leak or dangerous gases in the apartment unit(e.g. natural gas, carbon monoxide), whether there is unexpectedmovement within the apartment unit (especially useful for brokeragefirms and property owners that maintain an unoccupied unit).

Management Dashboard

The backend cloud computing service supports a management dashboard forenterprise users by summarizing information on and providing variouscapabilities, including battery life and Wi-Fi status across multipleapartment units and buildings, user usage across multiple apartmentunits and buildings, easy-to-provision new devices for new tenants andfor new apartments, onboarding and offboarding of tenants and roommatesthrough fleet management.

In some embodiments, multiple users may be affiliated with oneparticular intercom station under an umbrella apartment account (e.g.,members of a household). One roommate may be the administrator and maygrant other roommates certain permissions (including administratorstatus) to use the intercom station with their mobile devices.

Software and Firmware

In some embodiments, all intercom station software and firmware are ableto restore to a previous stable release through over-the-air downloadsto allow the user to return to a previously working version due toeither a failed update or an update that causes unanticipated failuresor breaks. The user is able to perform in-field software and firmwareupdates through over-the-air downloads viewable in the mobile app. Theseupdates would be downloaded from the AWS backend with staged releases ifrequired due to the number of devices in the field. This allows the userto add additional features to their devices and install security patchesas needed.

The intercom station is resistant to malicious interception ofcommunications by using on board crypto-encryption. In some embodiments,this is natively supported by the Micrium OS and the WGM160P module,which offers end-to-end encryption when combined with the securityprovided by the AWS IoT backend. Furthermore, end-to-end encryptionalleviates problems pertaining to ambient noise listening by theintercom that could lead to legal issues or customer concerns of theintercom stealing, recording, or transmitting unauthorized informationvia audio.

Intercom System in Action

FIG. 11 shows an illustrative flow diagram 1100 for unlocking a doorusing an intercom system from a station, in accordance with oneembodiment of the invention. Flow diagram 1100 begins at step 1101 byreceiving a request for unlocking a door at a base. In some embodiments,this request is performed when a guest presses a button on a panel thatcorresponds to the apartment unit. In step 1111, the base sends theunlocking request to a station. In step 1121, the station receives anapproval for unlocking the door. In step 1131, the station sends theunlocking approval to the base. In step 1141, the base unlocks the door.

FIG. 12 shows an illustrative flow diagram 1200 for remotely unlocking adoor using an intercom system, in accordance with one embodiment of theinvention. Flow diagram 1200 begins at step 1201 by receiving a requestfor unlocking a door at a base. In some embodiments, this request isperformed when a guest presses a button on a panel that corresponds tothe apartment unit. In step 1211, the base sends the unlocking requestto a station. In step 1215, the station forwards the unlocking requestto a mobile device. In step 1221, the mobile device receives an approvalfor unlocking the door. In step 1225, the mobile device sends theunlocking approval to the station. In step 1231, the station forwardsthe unlocking approval to the base. In step 1241, the base unlocks thedoor.

FIG. 13 shows an illustrative flow diagram 1300 for automaticallyunlocking a door using an intercom system, in accordance with oneembodiment of the invention. Flow diagram 1300 begins at step 1301 byreceiving a request for unlocking a door at a base. In some embodiments,this request is performed when a guest presses a button on a panel thatcorresponds to the apartment unit. In step 1311, the base sends theunlocking request to a station. In step 1315, the station forwards theunlocking request to a backend cloud-computing service (CCS). In step1321, the backend cloud-computing service approves the unlocking of thedoor. In step 1325, the backend cloud-computing service sends anunlocking approval to the station. In step 1331, the station forwardsthe unlocking approval to the base. In step 1341, the base unlocks thedoor.

FIG. 14 shows an illustrative flow diagram 1400 for unlocking a doorusing an intercom system with a virtual key, in accordance with oneembodiment of the invention. Flow diagram 1400 begins at step 1401 by ahost user activating a virtual key at the host user's mobile device. Insome embodiments, this activation is performed when the host user entersin the mobile app on the host user's mobile device relevant informationrelated to the virtual key, such as the name, e-mail address, and/orphone number of the intended guest; time periods when the virtual key isactive; or the number of times the virtual key may be applied. When theuser activates a virtual key, in step 1403, the mobile app sends avirtual key activation signal to the backend cloud-computing service(CCS). In step 1405, the virtual key is stored at the backend CCS. Instep 1407, the backend CCS sends the virtual key to a guest's mobiledevice, where the virtual key becomes active for the guest's use. Thevirtual key may be sent to the guest's mobile device in various ways,such as via e-mail, text message, third-party messaging applications(e.g., WhatsApp), or third-party applications (e.g., the Airbnb messagesystem). In step 1411, the guest applies the activated virtual key atthe guest's mobile device. In some embodiments, this application isperformed when the guest presses a virtual button on the guest's mobiledevice running a mobile app directed to a station. In other embodiments,this application is performed when the guest's mobile device running amobile app directed to a station breaches a geofence. In otherembodiments, this application is performed when the guest uses atelephone to call a service phone number and enter a unique FIN. In step1415, the guest's mobile device sends an unlocking request to thebackend cloud-computing service (CCS). In step 1421, the backend CCSapproves the unlocking of the door. In step 1425, the backend CCS sendsthe unlocking approval to the station. In step 1431, the stationforwards the unlocking approval to the base. In step 1441, the baseunlocks the door.

FIG. 15 shows an illustrative flow diagram 1500 for unlocking a doorusing an intercom system with a spoken password, in accordance with oneembodiment of the invention. Flow diagram 1500 begins at step 1501 byreceiving a spoken password entry at a base. In some embodiments, thisentry is performed when a guest presses a button on a panel thatcorresponds to the apartment unit and is prompted to speak a passwordinto the microphone of the panel. In step 1511, the base sends thespoken password entry to a station. In step 1515, the station recognizesthe spoken password entry. In some embodiments, this is performed byspeech recognition technology. In step 1521, the station determineswhether the spoken password entry matches or is sufficiently close to aset password. In step 1531, if the determination from step 1521 is yes,then the station sends an unlocking approval to the base. In step 1541,the base unlocks the door.

Exemplary System Architecture

An exemplary embodiment of the present disclosure may include one ormore servers (management computing entities), one or more networks, andone or more clients (user computing entities). Each of these components,entities, devices, and systems (similar terms used hereininterchangeably) may be in direct or indirect communication with, forexample, one another over the same or different wired or wirelessnetworks. Additionally, while FIGS. 16 and 17 illustrate the varioussystem entities as separate, standalone entities, the variousembodiments are not limited to this particular architecture.

Exemplary Management Computing Entity

FIG. 16 provides a block diagram of a server (management computingentity) 1602 according to one embodiment of the present disclosure. Ingeneral, the terms computing entity, computer, entity, device, system,and/or similar words used herein interchangeably may refer to, forexample, one or more computers, computing entities, desktop computers,mobile phones, tablets, phablets, notebooks, laptops, distributedsystems, gaming consoles, watches, glasses, iBeacons, proximity beacons,key fobs, radio frequency identification (RFID) tags, earpieces,scanners, televisions, dongles, cameras, wristbands, wearableitems/devices, kiosks, input terminals, servers or server networks,blades, gateways, switches, processing devices, processing entities,set-top boxes, relays, routers, network access points, base stations,the like, and/or any combination of devices or entities adapted toperform the functions, operations, and/or processes described herein.Such functions, operations, and/or processes may include, for example,transmitting, receiving, operating on, processing, displaying, storing,determining, creating/generating, monitoring, evaluating, and/orcomparing (similar terms used herein interchangeably). In oneembodiment, these functions, operations, and/or processes can beperformed on data, content, and/or information (similar terms usedherein interchangeably).

As indicated, in one embodiment, the management computing entity 1602may also include one or more communications interfaces 1610 forcommunicating with various computing entities, such as by communicatingdata, content, and/or information (similar terms used hereininterchangeably) that can be transmitted, received, operated on,processed, displayed, stored, and/or the like.

As shown in FIG. 16 , in one embodiment, the management computing entity1602 may include or be in communication with one or more processingelements 1604 (also referred to as processors and/or processingcircuitry—similar terms used herein interchangeably) that communicatewith other elements within the management computing entity 1602 via abus, for example. As will be understood, the processing element 1604 maybe embodied in a number of different ways. For example, the processingelement 1604 may be embodied as one or more complex programmable logicdevices (CPLDs), microprocessors, multi-core processors, coprocessingentities, application-specific instruction-set processors (ASIPs),microcontrollers, and/or controllers. Further, the processing element1604 may be embodied as one or more other processing devices orcircuitry. The term circuitry may refer to an entire hardware embodimentor a combination of hardware and computer program products. Thus, theprocessing element 1604 may be embodied as integrated circuits,application-specific integrated circuits (ASICs), field-programmablegate arrays (FPGAs), programmable logic arrays (PLAs), hardwareaccelerators, other circuitry, and/or the like. As will therefore beunderstood, the processing element 1604 may be configured for aparticular use or configured to execute instructions stored in volatileor non-volatile media or otherwise accessible to the processing element1604. As such, whether configured by hardware or computer programproducts, or by a combination thereof, the processing element 1604 maybe capable of performing steps or operations according to embodiments ofthe present disclosure when configured accordingly.

In one embodiment, the management computing entity 1602 may furtherinclude or be in communication with non-volatile media (also referred toas non-volatile storage, memory, memory storage, and/or memorycircuitry—similar terms used herein interchangeably). In one embodiment,the non-volatile storage or memory may include one or more non-volatilestorage or memory media 1606, including but not limited to hard disks,ROM, PROM, EPROM, EEPROM, flash memory, MMCs, SD memory cards, MemorySticks, CBRAM, PRAM, FeRAM, NVRAM, MRAM, RRAM, SONOS, FJG RAM, Millipedememory, racetrack memory, and/or the like. As will be recognized, thenon-volatile storage or memory media may store databases, databaseinstances, database management systems, data, applications, programs,program modules, scripts, source code, object code, byte code, compiledcode, interpreted code, machine code, executable instructions, and/orthe like. The term database, database instance, and/or databasemanagement system (similar terms used herein interchangeably) may referto a collection of records or data that is stored in a computer-readablestorage medium using one or more database models, such as a hierarchicaldatabase model, network model, relational model, entity-relationshipmodel, object model, document model, semantic model, graph model, and/orthe like.

In one embodiment, the management computing entity 1602 may furtherinclude or be in communication with volatile media (also referred to asvolatile storage, memory, memory storage, memory and/orcircuitry—similar terms used herein interchangeably). In one embodiment,the volatile storage or memory may also include one or more volatilestorage or memory media 1608, including but not limited to RAM, DRAM,SRAM, FPM DRAM, EDO DRAM, SDRAM, DDR SDRAM, DDR2 SDRAM, DDR3 SDRAM,RDRAM, TTRAM, T-RAM, Z-RAM, RIMM, DIMM, SIMM, VRAM, cache memory,register memory, and/or the like. As will be recognized, the volatilestorage or memory media may be used to store at least portions of thedatabases, database instances, database management systems, data,applications, programs, program modules, scripts, source code, objectcode, byte code, compiled code, interpreted code, machine code,executable instructions, and/or the like being executed by, for example,the processing element 1604. Thus, the databases, database instances,database management systems, data, applications, programs, programmodules, scripts, source code, object code, byte code, compiled code,interpreted code, machine code, executable instructions, and/or the likemay be used to control certain aspects of the operation of themanagement computing entity 1602 with the assistance of the processingelement 1604 and operating system.

As indicated, in one embodiment, the management computing entity 1602may also include one or more communications interfaces 1610 forcommunicating with various computing entities, such as by communicatingdata, content, and/or information (similar terms used hereininterchangeably) that can be transmitted, received, operated on,processed, displayed, stored, and/or the like. Such communication may beexecuted using a wired data transmission protocol, such as fiberdistributed data interface (FDDI), digital subscriber line (DSL),Ethernet, asynchronous transfer mode (ATM), frame relay, data over cableservice interface specification (DOCSIS), or any other wiredtransmission protocol. Similarly, the management computing entity (502)may be configured to communicate via wireless external communicationnetworks using any of a variety of protocols, such as general packetradio service (GPRS), Universal Mobile Telecommunications System (UMTS),Code Division Multiple Access 2000 (CDMA2000), CDMA2000 1× (1×RTT),Wideband Code Division Multiple Access (WCDMA), TimeDivision-Synchronous Code Division Multiple Access (TD-SCDMA), Long TermEvolution (LTE), Evolved Universal Terrestrial Radio Access Network(E-UTRAN), Evolution-Data Optimized (EVDO), High-Speed Packet Access(HSPA), High-Speed Downlink Packet Access (HSDPA), IEEE 802.11 (Wi-Fi),Wi-Fi Direct, 802.16 (WiMAX), ultra-wideband (UWB), infrared (IR)protocols, near field communication (NFC) protocols, Wibree, Bluetoothprotocols, wireless universal serial bus (USB) protocols, and/or anyother wireless protocol.

Although not shown, the management computing entity 1602 may include orbe in communication with one or more input elements, such as a keyboardinput, a mouse input, a touch screen/display input, motion input,movement input, audio input, pointing device input, joystick input,keypad input, and/or the like. The management computing entity 1602 mayalso include or be in communication with one or more output elements(not shown), such as audio output, video output, screen/display output,motion output, movement output, and/or the like.

As will be appreciated, one or more of the components of the managementcomputing entity 1602 may be located remotely from other managementcomputing entity 1602 components, such as in a distributed system.Furthermore, one or more of the components may be combined andadditional components performing functions described herein may beincluded in the management computing entity 1602. Thus, the managementcomputing entity 1602 can be adapted to accommodate a variety of needsand circumstances. As will be recognized, these architectures anddescriptions are provided for exemplary purposes only and are notlimiting to the various embodiments.

Exemplary User Computing Entity

A user may be an individual, a company, an organization, an entity, adepartment within an organization, a representative of an organizationand/or person, and/or the like. FIG. 17 provides an illustrativeschematic representative of a client (user computing entity) 1702 thatcan be used in conjunction with embodiments of the present disclosure.In general, the terms device, system, computing entity, entity, and/orsimilar words used herein interchangeably may refer to, for example, oneor more computers, computing entities, desktops, mobile phones, tablets,phablets, notebooks, laptops, distributed systems, gaming consoles,watches, glasses, key fobs, radio frequency identification (RFID) tags,earpieces, scanners, cameras, wristbands, kiosks, input terminals,servers or server networks, blades, gateways, switches, processingdevices, processing entities, set-top boxes, relays, routers, networkaccess points, base stations, the like, and/or any combination ofdevices or entities adapted to perform the functions, operations, and/orprocesses described herein. User computing entities 1702 can be operatedby various parties. As shown in FIG. 17 , the user computing entity 1702can include an antenna 1710, a transmitter 1704 (e.g., radio), areceiver 1706 (e.g., radio), and a processing element 1708 (e.g., CPLDs,microprocessors, multi-core processors, coprocessing entities, ASIPs,microcontrollers, and/or controllers) that provides signals to andreceives signals from the transmitter 1704 and receiver 1706,respectively.

The signals provided to and received from the transmitter 1704 and thereceiver 1706, respectively, may include signaling information inaccordance with air interface standards of applicable wireless systems.In this regard, the user computing entity 1702 may be capable ofoperating with one or more air interface standards, communicationprotocols, modulation types, and access types. More particularly, theuser computing entity 1702 may operate in accordance with any of anumber of wireless communication standards and protocols, such as thosedescribed above with regard to the management computing entity 1602. Ina particular embodiment, the user computing entity 1702 may operate inaccordance with multiple wireless communication standards and protocols,such as UMTS, CDMA2000, 1×RTT, WCDMA, TD-SCDMA, LTE, E-UTRAN, EVDO,HSPA, HSDPA, Wi-Fi, Wi-Fi Direct, WiMAX, UWB, IR, NFC, Bluetooth, USB,and/or the like. Similarly, the user computing entity 1702 may operatein accordance with multiple wired communication standards and protocols,such as those described above with regard to the management computingentity 1602 via a network interface 1716.

Via these communication standards and protocols, the user computingentity 1702 can communicate with various other entities using conceptssuch as Unstructured Supplementary Service Data (USSD), Short MessageService (SMS), Multimedia Messaging Service (MMS), Dual-ToneMulti-Frequency Signaling (DTMF), and/or Subscriber Identity ModuleDialer (SIM dialer). The user computing entity 1702 can also downloadchanges, add-ons, and updates, for instance, to its firmware, software(e.g., including executable instructions, applications, programmodules), and operating system.

According to one embodiment, the user computing entity 1702 may includelocation determining aspects, devices, modules, functionalities, and/orsimilar words used herein interchangeably. For example, the usercomputing entity 1702 may include outdoor positioning aspects, such as alocation module adapted to acquire, for example, latitude, longitude,altitude, geocode, course, direction, heading, speed, universal time(UTC), date, and/or various other information/data. In one embodiment,the location module can acquire data, sometimes known as ephemeris data,by identifying the number of satellites in view and the relativepositions of those satellites. The satellites may be a variety ofdifferent satellites, including Low Earth Orbit (LEO) satellite systems,Department of Defense (DOD) satellite systems, the European UnionGalileo positioning systems, the Chinese Compass navigation systems,Indian Regional Navigational satellite systems, and/or the like.Alternatively, the location information can be determined bytriangulating the user computing entity's 1702 position in connectionwith a variety of other systems, including cellular towers, Wi-Fi accesspoints, and/or the like. Similarly, the user computing entity 1702 mayinclude indoor positioning aspects, such as a location module adapted toacquire, for example, latitude, longitude, altitude, geocode, course,direction, heading, speed, time, date, and/or various otherinformation/data. Some of the indoor systems may use various position orlocation technologies including RFID tags, indoor beacons ortransmitters, Wi-Fi access points, cellular towers, nearby computingdevices (e.g., smartphones, laptops), and/or the like. For instance,such technologies may include the iBeacons, Gimbal proximity beacons,Bluetooth Low Energy (BLE) transmitters, NFC transmitters, and/or thelike. These indoor positioning aspects can be used in a variety ofsettings to determine the location of someone or something to withininches or centimeters.

The user computing entity 1702 may also comprise a user interface (thatcan include a display 1712 coupled to a processing element 1708 and/or auser input interface (coupled to a processing element 1708. For example,the user interface may be a user application, browser, user interface,and/or similar words used herein interchangeably executing on and/oraccessible via the user computing entity 1702 to interact with and/orcause display of information from the management computing entity 1602,as described herein. The user input interface can comprise any of anumber of devices or interfaces allowing the user computing entity 1702to receive data, such as a keypad 1714 (hard or soft), a touch display1712, voice/speech or motion interfaces, or other input device. Inembodiments including a keypad 1714, the keypad 1714) can include (orcause display of) the conventional numeric (0-9) and related keys (#,*), and other keys used for operating the user computing entity 1702)and may include a full set of alphabetic keys or set of keys that may beactivated to provide a full set of alphanumeric keys. In addition toproviding input, the user input interface can be used, for example, toactivate or deactivate certain functions, such as screen savers and/orsleep modes.

The user computing entity 1702 can also include volatile storage ormemory 1718 and/or non-volatile storage or memory 1720, which can beembedded and/or may be removable. For example, the non-volatile memorymay be ROM, PROM, EPROM, EEPROM, flash memory, MMCs, SD memory cards,Memory Sticks, CBRAM, PRAM, FeRAM, NVRAM, MRAM, RRAM, SONOS, FJG RAM,Millipede memory, racetrack memory, and/or the like. The volatile memorymay be RAM, DRAM, SRAM, FPM DRAM, EDO DRAM, SDRAM, DDR SDRAM, DDR2SDRAM, DDR3 SDRAM, RDRAM, TTRAM, T-RAM, Z-RAM, RIMM, DIMM, SIMM, VRAM,cache memory, register memory, and/or the like. The volatile andnon-volatile storage or memory can store databases, database instances,database management systems, data, applications, programs, programmodules, scripts, source code, object code, byte code, compiled code,interpreted code, machine code, executable instructions, and/or the liketo implement the functions of the user computing entity 1702. Asindicated, this may include a user application that is resident on theentity or accessible through a browser or other user interface forcommunicating with the management computing entity 1602 and/or variousother computing entities.

In another embodiment, the user computing entity 1702 may include one ormore components or functionality that are the same or similar to thoseof the management computing entity 1602, as described in greater detailabove. As will be recognized, these architectures and descriptions areprovided for exemplary purposes only and are not limiting to the variousembodiments.

The present invention may be implemented in a client server environment.FIG. 18 shows an illustrative system architecture for implementing oneembodiment of the present invention in a client server environment. Userdevices (i.e., image-capturing device) 1810 on the client side mayinclude smart phones 1812, laptops 1814, desktop PCs 1816, tablets 1818,or other devices. Such user devices 1810 access the service of thesystem server 1830 through some network connection 1820, such as theInternet.

In some embodiments of the present invention, the entire system can beimplemented and offered to the end-users and operators over theInternet, in a so-called cloud implementation. No local installation ofsoftware or hardware would be needed, and the end-users and operatorswould be allowed access to the systems of the present invention directlyover the Internet, using either a web browser or similar software on aclient, which client could be a desktop, laptop, mobile device, and soon. This eliminates any need for custom software installation on theclient side and increases the flexibility of delivery of the service(software-as-a-service) and increases user satisfaction and ease of use.Various business models, revenue models, and delivery mechanisms for thepresent invention are envisioned, and are all to be considered withinthe scope of the present invention.

CONCLUSIONS

One of ordinary skill in the art knows that the use cases, structures,schematics, and flow diagrams may be performed in other orders orcombinations, but the inventive concept of the present invention remainswithout departing from the broader scope of the invention. Everyembodiment may be unique, and methods/steps may be either shortened orlengthened, overlapped with the other activities, postponed, delayed,and continued after a time gap to practice the methods of the presentinvention.

Although the present invention has been described with reference tospecific exemplary embodiments, it will be evident that the variousmodifications and changes can be made to these embodiments withoutdeparting from the broader scope of the invention. Accordingly, thespecification and drawings are to be regarded in an illustrative senserather than in a restrictive sense. It will also be apparent to theskilled artisan that the embodiments described above are specificexamples of a single broader invention which may have greater scope thanany of the singular descriptions taught. There may be many alterationsmade in the descriptions without departing from the scope of the presentinvention.

What is claimed is:
 1. An intercom station apparatus for connection to alegacy intercom system, comprising: a station audio emission subsystemconfigured to emit a first audio signal; a station audio receptionsubsystem configured to receive a second audio signal; a talk featureconfigured to activate the station audio reception subsystem and alegacy base speaker; a listen feature configured to activate a legacybase microphone and the station audio emission subsystem; a wiringinterface for the legacy intercom system; a processor configured tointeract with and control the station audio emission subsystem and thestation audio reception subsystem; and an audio input-output circuitconfigured to process audio signals, comprising: a line input bufferconfigured to process audio signals from the legacy base microphonethrough the wiring interface for the legacy intercom system to theprocessor, comprising: a first electrostatic discharge and transientprotection subcircuit configured to receive a first input signal fromthe wiring interface for a legacy intercom system; a first galvanicisolator and voltage scaler subcircuit; and a first voltage buffercoupled to the first galvanic isolator and voltage scaler subcircuit,wherein the first voltage buffer is configured to transmit a firstoutput signal to the processor; and a line output driver configured toprocess audio signals from the processor to the legacy base speakerthrough the wiring interface for the legacy intercom system, comprising:a second voltage buffer configured to receive a second input signal fromthe processor; a high-pass filter coupled to the second voltage buffer;a second galvanic isolator and voltage scaler subcircuit coupled to thehigh-pass filter; and a second electrostatic discharge and transientprotection subcircuit coupled to the second galvanic isolator andvoltage scaler subcircuit and configured to transmit a second outputsignal to the wiring interface for the legacy intercom system.
 2. Theintercom station apparatus of claim 1, wherein the station audioemission subsystem is a station speaker, wherein the first audio signalis sound, wherein the station audio reception subsystem is a stationmicrophone, and wherein the second audio signal is sound.
 3. Theintercom station apparatus of claim 1, wherein the first voltage bufferis a first operational amplifier, and wherein the second voltage bufferis a second operational amplifier.
 4. The intercom station apparatus ofclaim 1, wherein the first electrostatic discharge and transientprotection subcircuit comprises a first electrostatic discharge resistorand a first transient-voltage-suppression diode, and wherein the secondelectrostatic discharge and transient protection subcircuit comprises asecond electrostatic discharge resistor and a secondtransient-voltage-suppression diode.
 5. The intercom station apparatusof claim 1, wherein the first galvanic isolator and voltage scalersubcircuit comprises a first transformer, and wherein the secondgalvanic isolator and voltage scaler subcircuit comprises a secondtransformer.
 6. The intercom station apparatus of claim 5, wherein thefirst transformer is 1:1.
 7. The intercom station apparatus of claim 5,wherein the second transformer is 1:1.
 8. The intercom station apparatusof claim 5, wherein the first galvanic isolator and voltage scalersubcircuit further comprises a first voltage scaler coupled to the firsttransformer, and wherein the second galvanic isolator and voltage scalersubcircuit further comprises a second voltage scaler coupled to thesecond transformer.
 9. The intercom station apparatus of claim 8,wherein the first voltage scaler comprises: a first voltage dividercoupled to the first transformer, and a second voltage divider coupledto the first voltage divider; and wherein the second voltage scalercomprises a third voltage divider.
 10. The intercom station apparatus ofclaim 9, wherein the first voltage divider comprises a plurality ofresistors, and wherein the first voltage divider generates a ratio ofapproximately 50%.
 11. The intercom station apparatus of claim 9,wherein the second voltage divider comprises a plurality of resistors.12. The intercom station apparatus of claim 9, wherein the secondvoltage divider biases a signal to around half of a supply voltage. 13.The intercom station apparatus of claim 9, wherein the third voltagedivider comprises a plurality of resistors, and wherein the thirdvoltage divider generates a ratio of approximately 4.5%.
 14. Theintercom station apparatus of claim 5, wherein the high-pass filtercomprises a capacitor with a capacitance based on an impedance of thesecond transformer.
 15. The intercom station apparatus of claim 5,wherein the second transformer comprises a plurality of windings, andwherein a DC resistance of each winding of the plurality of windings ofthe second transformer is greater than a resistance of a legacy stationspeaker.
 16. The intercom station apparatus of claim 5, wherein thesecond transformer supports a signal range of 200 Hz to 4,000 Hz. 17.The intercom station apparatus of claim 1, wherein the line input bufferfurther comprises a voltage-limiting subcircuit coupled to the firstvoltage buffer, wherein the voltage-limiting subcircuit limits an inputto the first voltage buffer to within a predefined threshold.
 18. Theintercom station apparatus of claim 17, wherein the voltage-limitingsubcircuit comprises a Schottky barrier diode.
 19. The intercom stationapparatus of claim 1, wherein the intercom station apparatus isconfigured to interact with a base and a backend cloud-computing service(CCS).
 20. An intercom station apparatus for connection to a legacyintercom system, comprising: a station audio emission subsystemconfigured to emit a first audio signal; a station audio receptionsubsystem configured to receive a second audio signal; a talk featureconfigured to activate the station audio reception subsystem and alegacy base speaker; a listen feature configured to activate a legacybase microphone and the audio emission subsystem; a wiring interface forthe legacy intercom system; a processor configured to interact with andcontrol the station audio emission subsystem and the station audioreception subsystem; and an audio input-output circuit configured toprocess audio signals, comprising: a line input buffer configured toprocess audio signals from the legacy base microphone through the wiringinterface for the legacy intercom system to the processor, comprising: afirst galvanic isolator and voltage scaler subcircuit configured toreceive a first input signal from the wiring interface for a legacyintercom system; and a first voltage buffer coupled to the firstgalvanic isolator and voltage scaler subcircuit, wherein the firstvoltage buffer is configured to transmit a first output signal to theprocessor; and a line output driver configured to process audio signalsfrom the processor to the legacy base speaker through the wiringinterface for the legacy intercom system, comprising: a second voltagebuffer configured to receive a second input signal from the processor; ahigh-pass filter coupled to the second voltage buffer; and a secondgalvanic isolator and voltage scaler subcircuit coupled to the high-passfilter and configured to transmit a second output signal to the wiringinterface for the legacy intercom system.